Why we sell digital pianos?
In my School I chose to use and sell digital pianos as opposed to acoustic upright and grand pianos for a few reasons; The built-in headphone jacks allows me, and students while at home, to plug in stereo headphones for private practice, plus digital pianos do not go out of tune like acoustics. Acoustic pianos, no matter what the brand, model, or size, do go out of tune, sometimes often because of fluctuations in weather humidity levels, especially in Florida, and have to be tuned at least twice a year ….for a cost, while Digital pianos are not affected like that and they stay in tune no matter what.
The younger generation want their piano to give them a complete interactive music playing and listening experience which only digital pianos can really do. All our new Casio Privia digital pianos, can connect directly with an iPad or laptop computer using its high speed class compliant USB MIDI connection which allows for instant connection with external computer devices without the need of downloading drivers or having to convert a MIDI signal to USB. Since kids are growing up in the "iPad world" I recommend to all piano students that they utilize the exciting Apps available for tablets (and iPad in particular) to enhance their playing and practice experience which will make them better students and better musicians overall. When you've experienced the interaction of the Casio with an iPad and what it can musically and educationally do for you, you'll be amazed at all the possibilities!
Generally speaking, if you're a piano student, a person who wants to have fun with their music and enjoys hearing different instrument tones with built-in music education features, you like & need the headphone feature, you don't want to pay hundreds of dollars in piano tuning maintenance, or you like the idea of using computer music software to enhance your playing and learning experience, then purchase a good new digital piano and you'll be glad you did.
In our school we practice on and sell four models of Casio Privia Digital Pianos, PX150, PX350, PX780, and PX850, all under $1100.
 Why we chose Casio Privia? 
First I prefer the Casio Privia type of piano weighted key action for my piano students and for people interested in reproducing the acoustic piano key weight and action as closely as they can. Piano tone is always number one concern of piano teachers and those people that can play piano at higher skill levels. All models of Privia we sell are superior instrument in many ways including acoustic piano sound & much more realistic graduated hammer key action, wider piano dynamics, and longer decay/sustain time. As far as key action movement and dynamic response goes, all Privia models are surprisingly realistic. This is because they have a higher level of acoustic piano sound realism and 3-sensor weighted hammer key action technology for faster repetitive action recognition. Unless you were a fairly good piano player, you might not be able to tell much difference between an actual acoustic piano  as far as touch & piano tone, especially when listening through a good pair of headphones, (the on-board speakers are good for a  piano), but connecting to an external speaker system through audio outputs would be even better.
As far as the piano keys themselves go, the better digital manufacturers have come out with a new synthetic "ivory feel keytop" on many digital pianos which is a new material on top of the white keys that tries to reproduce the original real ivory keys. The ivory substance provides a better playing experience for most people because it absorbs sweat your fingers would produce while playing the keys and this material also provided a smoother key surface as well and doesn’t feel like plastic. The black key tops are made of ebony so the black keys also had a better playing surface. To get these new keytops instead of the regular plastic ones, you would need to spend around $1500 or more to get it on digital pianos these days. And beyond that, this new material is not the same on different piano brands because some are noticeably better than others. Casio has added a proprietary synthetic ebony and ivory to their keys that I really like and it's quite a bit better than the next nearest competitor with ivory feel keys, which is Roland. So I give Casio a lot of credit for coming out with such a nice feature at a much lower price than anyone else.
To reproduce the sound of the finest acoustic grand pianos, all new Privia series features Casio’s proprietary  AiR (Acoustic and intelligent Resonator) processor. Accessing more than three times the memory of the previous generation, the AiR processor utilizes grand piano samples recorded at four dynamics sampling to deliver grand piano sounds with long natural decays and remarkable expression. The result is unprecedented, natural-sounding digital reproduction of the playing and sound properties of a concert-quality grand piano sound in your own home.
All models we carry have different instrument tones, many of which are various acoustic piano sounds which is one of the most important features to have on a digital piano. A good variety of acoustic piano tones allows you to play and reproduce different types of piano music including classical, jazz, pop, country, etc. There are a few newer digital pianos from other brands, but they typically have only two acoustic piano sounds. So having variety of them is very good.
One important future in all digital pianos is “polyphony”. What is it?
Digital note and sound memory in many cases is referred to as "polyphony. Long time ago when there was only 8 notes of polyphony. If you were playing more than 8 keys at one time in both hands each sound took up a note of polyphony when you played the keys! and you couldn't hear everything you were playing because the piano ran out of memory! Notes would drop out as well as sounds and it made the music sound bad. And if you tried to record that on a digital recorder, it would only play back a few notes and sounds at a time and the song would continually be interrupted by the loss of polyphony or memory.  Then came more sophisticated tones like stereo acoustic piano sounds with natural acoustic quality harmonics, overtones and string samples and more complex left hand accompaniments which all sucked up digital memory like a sponge. Now manufacturers have started to figure out how to put more polyphony memory and other ingredients (including more cool sounds) at a lower cost (cost is always an issue) into one keyboard or digital piano so you don't need to have (own) more than one instrument. So basically, more polyphony "frees up" your music so you can use all the functions on the digital piano to their maximum. However, I will say that in some cases, 64-notes of polyphony will probably be adequate for certain people depending on how they play, although having more polyphony is a good thing.  But if you want to progress as a player and eventually learn how to use more of the functions in your keyboard or digital piano (including recording your music up to 16-tracks), then be sure to get as much "polyphony" as you can for your budget. It's like buying a computer these days...you may not use all the memory and speed it has right away, but you may want to know it's in there in case you do need it.  More polyphony note memory helps to keep notes from electronically dropping out when playing difficult & musically complex passages. One of the biggest advancements not offered on any other digital piano brand in this price range is the new 256-note polyphony piano sound memory technology used in our flagship Casio Privia PX-850. Even the highly respected Yamaha AvantGrand digital grand piano selling for approx $15,000 has the maximum 256-note polyphony technology which makes Casio's achievement pretty amazing.
For some people, the Casio brand may not have the prestigious piano name of a Yamaha, Kawai, or Roland, but the name itself seldom tells the real story and that is certainly true in this case. I have played all of the new pianos out there including these brands, and other, but in this price range, there is really nothing else right now that comes close to the new line of Casio Privia pianos. So don't let the Casio name fool you into thinking Casio Privia pianos are not worthy because in my opinion the they are the real deal
The Casio Company has its worldwide headquarters in Tokyo, Japan, and has been producing digital pianos for over 30 years. Casio produces their own computer chips and proprietary micro technology and is able to do it at a fraction of the cost of some of its biggest competitors. That is why Casio tends to have lower prices. (it's about price for most people) Some people equate lower prices with lower quality but in my opinion these new Casio digital pianos are very impressive. There are also no "best brands" in my opinion but just some great brands that offer fine products in their respective price ranges and Casio does a brilliant job in the lower price range .Beyond that, Casio Privia has a new 3-year parts & labor warranty which shows they are serious about giving consumers product protection and have confidence in their new pianos. Most warranties on digital pianos under $1000 have no more than 1 year labor or maybe 2 at the most, so 3 years is outstanding in my opinion. When a manufacturer provides a long factory warranty such as 3 years, it's a signal to me that their product will hold up and last for a long time, which is always a good thing.