I used one for YEARS. Yeah, they're nothing special, but they've got a solid Fatar keybed, and they can be programmed extremely quickly. It doesn't have a lot of built-in advanced performance options, but considering I moved to software directly from a QS8, I'm not sure what more recent boards offer either. If you plan on doing a lot of different Mix presets for live performance (like I did), i would recommend getting an SRAM card so you're not saving over existing presets.
As a controller, I only just retired mine last year (I got mine in 99), I switched to using it as a controller with a laptop about 7 years ago, but I recently got an Arturia Keylab88, as many controllers and wheels were starting to die and it was just time to lay it to rest.
Good organs and electric pianos. Unfortunately the piano sound is pretty iconically terrible, and the lack of resonance filter makes subtractive synth programing pretty limited, but the presets are surprisingly good.