Just really started getting into the pro53...the sound isn't amazing (although I always beef these things up through a valve compressor out of the box) but it's the first synth I've been able to really understand whats going on when I'm tweaking things and it's helped me get the concept of it all...I come from a strictly guitar based background so adopting this technology (no matter how old it is!) is all a bit new. I've no idea where to start with the Jupiter, i've just been going through all the presets and tweaking from there (same with Massive) but I would be really lost if I hadn't learnt some stuff on the pro53. Native Instruments is all good stuff to my ears... (B4, Battery, Elektrik Piano etc. as well as Guitar Rig) The Arturia stuff is great also. That's about all I play with. Another cool one is Rob Papen's Albino, they have a new one out called Predator that looks good aswell.