Hi
John. Yes I don't have a decent enough computer to run X1/X2 but when I do get such a system I might give it a try. Another good thing about Studio One is that it runs on any computer and any OS as well.
This Instrument definitions argument is weak actually. It implies you are using presets all the time which I don't that much. If you edit a patch and store it somewhere else how does Sonar know of it's location anyway.
I find that the more pro work I seem to do the more I am editing patches and also bringing in other sounds from sound libraries etc into Kurzweil and EMU machines. Inst defs don't know anything about that.
I am of the opinion you should know exactly what preset any synth may be using at any instant. You need to find it, select it, maybe edit and use it. Th synth itself is the best thing to use to find sounds, not your software. That is how I work. And once happy I turn that into audio usually. And if I don't I simply either store it somewhere so the next day it loads back anyway. Or I make a note inside Studio One as to what the preset is and where it came from etc. For me lack of Inst definitions is not a game changer.
For something like a Kurzweil for example the Inst defs may be great for the 200 or so internal presets that are there but what about the million other sounds that are on my CD ROMS and hard drives. They are useless for those. They won't know about them. You have to physically search libraries and bring them in and use them then.