I did a trial for this a while ago. The GUI Is stunning. To be honest though I didn't give it enough time to learn my way around it properly but it seems nice. I think the main thing they boasted was the improved workflow features.
Anyway, give it a shot, it seemed good but im a cubase fan boy
I have Studio One v1.6.5, Studio One v2.0.3, Reason 5, and Cubase 5
Try out Studio One v1.6.5 it runs like a dream and is really stable with very low cpu usage. I have Studio One 2.0.3 but have issues with it running up my cpu at about 75% while its just sitting there and then creates clipping when doing anything etc.... apparently a rare issue but it has affected a few on the forums it seems.
But as I say v.1.6.5 is what I use and really enjoying. You can rewire in reason with a simple drag over of the instrument and then load up reason job done. Done it a few times now but i'm trying learning how to do as much as possible in just Studio One itself which i'm finally managing to do. I used to just rewire reason in for doing drums and such.. but now working them well with impulse within Studio One.
I can't seem to get my head around or into Cubase. I guess i'm a nice GUI user as apposed to a win 3.1 looking program lol I know looks arn't everything of course but I just really can't get to grips with it, I get frustrated and just end up wasting my time which I don't have a lot of.
If you want any more info or anything about Studio One I'd be more then willing to try and help lol.
Theres a lot more too it then meets the eye to be fair. A lot of stuff isn't found straight away in menus and such, its more shortcuts and mouse clickable area options then menus etc.
Such as to stretch a audio sample was impossible in menus until i watch a tutorial on their website and found out its as simple as holding ctrl+alt then dragging the end of the sample to where i wanted it to stretch to. lol
Once you learn the little tricks such as the fading options just click in the top end corner of a block and you can adjust the fade... takes less then a second to do...