As a professional musician, I perform in a range of venues from concert settings to receptions and few keyboards have compared in sound quality to the Yamaha line. I appreciate the controllers and the ease of navigation which allows me to find nice sounding patches fairly quickly. The only gripe I could express is that the weighted keyboard can be rough on your fingers if you play hard. Unlike their clavinova series whose keyboard action is inspiring and yet you can slide your hand up and down the keyboard without pain, for some reason I have found the S70XS much heavier and have left gigs with fingers bloodied on occasion. Perhaps it is the graded hammer action and there may be a way to adjust this but I have yet to discover it. Anyway, it still earns 5-stars for not requiring a "wall wart" plug for power and for exceptional control and inspired sound quality. It is terrific to play for a pianist. An organist may run into the challenge I did with painful glissandos. I would definitely buy it again although I do wish it were slightly shorter as it is virtually an 88-note keyboard size with only 76 keys. Still, awesome in every important area. True professional feel and sound. Robust library and feels like it will last.

I bought one of these 8-9 years ago when they came out. I was playing out a lot at that point, and so I bought the 76-key version because it fits better in the back seat of a car. There are very few pieces that I play that require the ends of an 88-key keyboard, and so this was perfect for playing out. These days, I'm not interested in gigging anymore, and so I decided to get an 88-key piano/synthesizer. I assumed that there would be something invented over the last decade that I would like better, but in the end, I decided to get another XS: the Yamaha S90-XS.

These have a great hammer-action keyboard and very fine pianos, which are the sounds that are probably the most difficult to make and use the most memory. I want to address a comment from another reviewer about the piano who said: "The much vaunted s6 piano sound suffers from awful harmonics on the C#1, D1 and D#1 keys." This reviewer is entirely correct. This is the one fly in the ointment of this instrument. To address this issue, I made layers that use these three low notes from a different piano. This is not difficult once you become familiar with programming this instrument, which I now find very easy. For me, this solves the problem. I used to compare these pianos with the piano samples of Nord, and I liked these pianos a lot better. (I was using a Nord Electro 3 and was playing it via the hammer-action keyboard of the Yamaha. It could be that current Nords have better pianos.)

Probably the worst sounds on a Yamaha are the Hammonds. But then again, mine is sitting next to my Hammond C3, and so it's easy to be critical. (For a great and inexpensive Hammond in a box, try the HX3.) Most synthesizer sounds are very good. It's not an analog synthesizer (like my Dave Smith Instruments), and so the analog sounds are going to sound better on something like my Prophet Rev 2's. But so many other sounds are better on a digital keyboard like this Yamaha (e.g., electric pianos, church organs, reeds, orchestral strings, drums, etc.) Having said that, there are a lot of great analog type synthesizer sounds in this instrument.

A great feature of this instrument is that it has a mic jack, and another is that you can record onto a thumb drive whatever you are playing and singing. So you can record your singing and your piano accompaniment. I've used this recording feature many times. I've even used the mic jack to record some acoustic guitar solos and pieces that use another synthesizer going into the mic jack.

I have a Yamaha S90XS and I think it's a great keyboard. Very nice piano action and the sounds are very professional sounding. Unlike the previous reviewer, I have not had any dropped note issues. I am a pianist by background and play fairly fast classical music passages. This keyboard responds and sounds just like a grand piano would. The variety of sounds available on this keyboard are endless. Highly recommended.

The Yamaha S70XS.......Top of the line build quality, and has 76 piano action keys with aftertouch and all the Motif XS sounds with added pianos.....

It could have been an awesome and compact gigging board but instead of putting the two wheels above the keys like on the Yamaha MO8 & MOX8, they put them to the left of the keys and made it so wide, you might as well be hauling 88 keys......what a screw up !!!! That board could have gotten by with about an inch of keyboard on the left and right of the keys and been super compact and a dream to move.

I don't need more than 76 keys really.....76 keys is enough for most rock music especially since it has both transpose buttons and octave up & down buttons. Someone should beat Yamaha like a stepchild for that decision.

You think that's big, the S90XS has all 88 keys and the same added width. All the Motifs with 88 keys are the same way but maybe a little less wide than the S90XS.....not by much though. Making boards as compact as possible should be a top priority for any company making them. They don't have to fit them in their car or lift them. They probably figure that the bigger they are, the more they can charge.

I've owned this keyboard for over a year, and I LOVE it. It's very much like owning a MOTIF, only lighter and slightly easier to program. As a vocalist who plays keys, I really appreciate the mic input when I'd like to control my own volume and reverb in relation to my keys. As far as sound quality, much depends on what you're using it for. The piano sounds are wonderful in our church, but it does take a little tweaking because every space is different. I have to roll off a lot of low end on piano and organ. I layer a grand, EP, pad, and organ and this gives me just about everything I need for basic sounds. I use Mainstage for more in-depth synth and arp programming. If this board were still on the market and maybe a little lighter and shorter, I'd choose it over any other board out there - even a Nord.