Been using albeton recently working on a live set which is a giggle for throwing things together but then you get half way through an idea and get stuck and its' copy all the loops back into Protools time and then make 'em how you want them and then stick them back into Ableton.

I guess it's possible to do it all in ableton but it'd be a right pain!

Recently though even in protools things are in more than one session, less so with the dancey stuff and more with the pop and shit there'll be a seperate session with just the vocals in or just one sound that's made up of lots of bits and then that'll all get bounced down to audio and loaded back up into the main session.