Hey,
A good producer will make a KILLER beat using a cell phone and a rubber band, if he knows what he's doing. What you've laid out before us is an example where you have mediocre producers relying on the quality of their gear instead of the quality of their knowledge. A good producer will use whatever tools he has before him to make a track, be it a full blown studio or a stick of chewing gum.
Sure, a 3 year old with a Triton can make a better 'sounding' beat than someone with experience using a PSR because the difference in quality is SO big...
...but I'll bet you the good producer will sample the sounds off the PSR into something like a computer, spice them up with effects and eq, edit them, etc., and deliver a product that will make most Triton newbies look a bunch of rich kids.
In the case where both producers are of equal calibre, the PSR guy will have to work a little harder to get the results he wants because his keyboard won't have as many options as the Triton, but he'll get the job done. Just listen to some of the beats here at Illmuzik, they sound pretty damn good and some of the users don't even have real hardware.
But what if the client is looking for a 'low fi' sound that would be hard to replicate on a Triton? Then the PSR guy will be laughing his ass off at the Triton guy, collect $500, and take the Triton guy's girlfriend out to dinner.
Take care,
Nick