The Pro-version's got a direct signal out (reamping or live-usage combined with a real amp). The digital ins are really important, because if you use better ADs the whole thing will sound much better.
Greetings, Henning
EDIT: Ooops, I just noticed, that you are asking for XT and XT Live (not for Pro). The inputs and algorithms (and therefore the tone) are the same. It's just the floorboard, the pedal and the FX-pack.