1st thing I would like to point out is that my observations below are purely of the demos, not the instruments themselves as I have not heard them live, so the demo may or may not be representative of them.

2nd thing is I am out regular listening to live music of various types and this is what I will be basing my opinions on. (Not in comparison with any other keyboard or recording)

Cool Swing and Acoustic Jazz

Korg gives quite a reasonable sound and certainly has a live feel to it; however the Yamaha is way out of its depth sounding very old. (There is no way it could be mistaken for a real instruments and players)

Piano & Strings

Both Pianos are different but neither gets above ordinary and boring, as to the strings then what have Korg done, as they are the worst strings I have heard in a long time, the Yamaha on the other hand is a more integrated sound but is 1 dimensional and lacks any of the expression that you get with a real string orchestra. (This is possibly because the player is not using an expression pedal though)

Unplugged Style

This is very nicely done on the Korg with quite good realism from most of the instruments and style used, the Yamaha on the other hand has no realism at all and the guitar in the style is diabolical. (Sorry Yamaha but you need a lot more work on this part of the instrument)

Orchestra

Good sounds from both with the Korg sounding the most live; however without an expression pedal there is no chance of either of them sounding remotely like a proper orchestra.

Country Strum

Korg sounds are ok but it sounds like the band is not really interested in what they are playing thus you don’t get the full foot tapping urge, once again the Yamaha guitars really let it down and the style just sends you off to sleep. (You can forget getting folks up to dance or to get their feet tapping with this one Yamaha)

Blues

Always difficult to pull off as there are so many variations, again the Korg sounded as if the musicians where not interested in what they were playing, while the Yamaha was once again very poor in comparison with more work needed to be done by Yamaha to bring it up to scratch.

Overall

The Korg shows good potential but lacks the tightness of the PA800 it replaces, however Korg usually bring out an update that addresses most of the issues. (The PA800 was also rather lacklustre when it first came out)

The Yamaha however appears to be just recycling its past, which means its falling behind in a lot of departments and in many respects is only a small update to the S910 it replaces. (Certainly wouldn’t be worth upgrading an S910 for it unless you were really desperate for the few updates)

Would I buy either from the demos? The answer has to be no, as neither of them float my boat.

NOTE: As I mentioned at the beginning my opinion is purely based on the demos and not the instruments themselves, as I have not tried them myself and so cannot confirm any of their sound & style capabilities.

Bill