I'm really not into the whole "Ableton in a box" thing, but a few tricks that I think would be sweet to borrow from Live are "set 1.1.1. here," follow actions, and legato pattern triggering.
To explain the first: I know I'm not the only one who gets a nice pattern going with live recording, only to discover the downbeat is actually on step 8 or wherever. Ok, func+arrows to push each track back... not too painful. HOWEVER if the sound you really want to be smack on 1.1.1. is microtimed, you're screwed, because you would have to manually shift the microtiming of every other trig on every other track. So how about trig+tempo or something to set 1.1.1. and shift all other trigs accordingly? Having to stop playback for this would be fine by me...
Follow actions and legato patterns would just be icing on a cake that's arguably too rich already, and there's a good chance I would never use them if implemented anyway
But legato with scenes and parts seems to have awesome potential...