Keep in mind, guys, the PSR-3000 was well ahead of it's time when it was released, then the OS was updated to 1.8, which improved several features. It took me several years to discover all the features, and though I'm fairly proficient with the 3000, I'm equally confident there are things I did not discover about the inner workings of the keyboard.
As for as the overall sound, some are superior to the newer voices, such as the Growl Sax, some of the guitars, and the vibes. I ended up modifying the Grand Piano voice, posted it on the various forums and it has been downloaded several thousand times by users who claim it is their Go To piano voice for all Yamaha arranger keyboards they have owned, including the Tyros and Genos.
That said, there has been significant improvements in some of the voices, such as the newer SA voices and of course, the audio styles, which are superb by every stretch of the imagination. Unfortunately, the vast majority of our audiences never seen to hear these things, therefore, the only person that usually hears these things are the musician/entertainer.
Of course, playing skills and technique has a lot to do with what comes out of the the PA system, hence, players like DonM could use just about any arranger keyboard, or a comb with wax paper stretched over it, and entertain an audience just about anywhere. Keep in mind, though, that he was born with an arranger keyboard at his fingertips, he spent lots of time working with the various Operating Systems and get the most out of each and every aspect or feature he has delved into. And, that, my friends, is what it takes.
Good luck on whatever you decide upon,
Gary