I think that by the time you run the keyboard through the pa, add crowd noise, etc., the sounds on virtually every current keyboard are more than adequate.
If you get into a studio situation, with intricate recording of tracks, it would be a different story. Still it would take a fairly critical ear to find fault.
I'm still pleasing people with Roland E50 from time to time.
DonM
The differences are subtle with some sounds, and markedly so with others.
In the case of the Tyros4 and S950, the latter has a lot of Tyros4 sounds, but it does not have Super Articulated II sounds, and some of these are absolutely the pinnacle in expressiveness.
On the other hand, in most cases, with a skillful player, the MOTL arranger will do any type gig just fine...I've done many with S910 and S900 as well as the old PSR-3000, and through a decent PA system, these keyboards are more than adequate.
However, some of us like to have even more control over expressivity, so we buy instruments with more versatile sounds and sound control, like the T4 and the PA3x, that have superior voices and aftertouch control, as well as a more pro synth feeling keyboard.
Plus, we can add more sounds, and in the case of the Tyros4, the SA2 voices can be used in the styles...the S950 having only SA, is at a bit of a disadvantage.
Do we need a TOTL to sound good and to cover our gigs?
Nope, we don't, but for some here on SZ, the high end stuff is what we WANT...G-70's instead of E-60's, Tyros4's instead of S950's, and PA3x's instead of PA-600's.
I can safely say that playing the Tyros4 is a far more satisfying experience for me, the player, than is a PSR-S910 or S950.
Instruments are very
personal...even arrangers.
Ian