Hi Alex
Thank you for your post. Yes realtime looping is becoming more and more popular. I have an RC20 which is great as far as it goes. But you are surely still having to use another I/O to get the audio into the mac in the first place. Also how are you syncronising the RC20 with Live? It doesn't have either the midi or usb functionality that the RC50 does.
Also you seem to suggest you are moving clips around after you have recorded them, is that right? Personally if I'm performing I'd prefer to have the option not to have to turn my focus to a computer screen. I've been bowled over by what Kid Beyond does - as regards Live looping. Please check out his Ableton demo either at the ableton website or his own
http://www.kidbeyond.com/
It should blow you away. Also we have a lovely guy in London who is a brilliant Bass looper
called Steve Lawson. He use 2 Gibson echoplexs, and has lots of video clips on his site. V. informative. But bhe is I believe checking out "Live"
Hope some of this is helpful.
I still haven't worked out how to do what Kid Beyond does on a Mac. And I think Live ought to have a menu dedicated to "Loopers" to make it easier. I bought Live 1 within days of it coming out... mainly because I thought it was a live looper.
Best Wishes
Rich in London