Feature:
Way more features than I'm ever gonna use.

Quality:
Like all Yamaha stuff, the S90 is designed to last, and is very solid. This one lives in my studio, but I wouldn't hesitate to take it on the road. (It is a big, heavy keyboard though - no fun to carry.)

Value:
Pricing is right in line with comparable keyboards.

Desirability:
By far the best 88-key weighted action around. Light, fast, very similar to Yamaha's piano action in feel. In fact, I bought it mostly for the action, as a controller, after trying every weighted keyboard I could get my hands on.

Sound:
This is a great sounding keyboard. Overall, I love it. One minor complaint. The multisampled piano is clean and light -- great at low and middle volumes, but they don't seem to have sampled really hard attacks. It just doesn't thunder quite like a real piano, or even like the better Gigastudio pianos. It also doesn't model damper noise or pedal-down resonance. So,in the studio, I'm sticking to real piano, or at least one of the "big" sampled pianos (with the S90 as controller). But I'd still be happy to play the S90 live vs. most of the pianos out there in the world.

Support:
The only problem I've ever had with any Yamaha equipment is that the floppy drive belt on my SY77 broke after about 10 years of use. I fixed it myself and continued on my way. Yamaha is good about updating drivers and software via their website, and there's a big group of users and 3rd party sound designers out there on the web.

Overall:
Over the last 20 years, I've owned synths from every major manufacturer. Most of 'em haven't lasted. Either they break, or their sounds go out of date. Not my Yamaha stuff though -- I've still got my DX7 and SY77 from the early 90s, not to mention a C6 grand piano. I'm planning on owning my S90 for a long, long time.

Feature:
The controls are sensibly placed and easy to manipulate.

Quality:
It's a Yamaha!

Value:
Since I was able to trade in a Yamaha P80 Piano, Korg Karma Synthesizer and a Korg CX-3 Organ towards one keyboard that beats all three, I'd say it was an excellent value.

Desirability:
I wanted the sounds and I wanted the incredibly responsive keyboard. Like the man says, "It has everything I want and nothing I don't want".

Sound:
All the sounds are very authentic and useable. Noteworthy are the outstanding piano and organ presets.

Support:
I haven't had any need to contact Customer Support. The Owner's Manual is very thorough and Yamaha's Internet User's Group Website is outstanding.

Overall:
This awesome keyboard has and will continue to serve me for a long long time.

Feature:
Excellent amount of features, I found that this piano is not only loaded with its own built in sounds, but you can plug a USB cable into your laptop and use it as a MIDI controller. Though you may not want to considering the built in sounds are very suitable for any on stage or studio need. *I use an M-Audio Prokeys currently, I plug that into my laptop and use the MIDI features in Apple's Logic Pro. Im satisfied with the sound.. but horrified at the terrible action and velocity response of the keyboard. This Piano took only minutes to commit me into a buy, and 95 minutes later I was ready to hand over my debit card.

Quality:
Close your eyes, sit back, & it feels like your sitting at a baby grand.

Value:
High quality construction, I would like to believe thats real wood on the side.. but its only laminated. None-the less the keyboard is very very well built.

Desirability:
If your still using a semi-weighted midi controller, or your neighbors casio keyboard this piano makes a wonderfull addition to any musicians collection, as well as being able to show of a professional grade instrument.

Sound:
This piano is far from entry level, not as hardcore as a Motif workstation but it packs the same spirit, & has a great value for only 1,300 dollars. Excellent action as well as very well timed velocity and feedback response.

Ease of Use:
"plug and play" a little hunting around to find the transmition features for use of the USB interface overall not bad.

Support:
I just played it in the store for about an hour.

Overall:
Im in the process of buying one, and I do believe I will be satisfied for a long time.

The keyboard action is one of the best I've tried and I love the sounds - particulary the pianos, keyboards, organs, synths. There's also plenty of scope for programming your own sounds. It works well both as a stand-alone instrument and for sequencing when linked to a PC. The build quality is excellent.

This is a top notch keyboard for those who want all the bread and butter sounds and can live without an onboard sequencer or plan on using a computer-based one. The action on this guy won me over -- killer. Decent-sized menu based screen makes it not *too* hard to use.