if your doing a really involved mix with edits, tempo changes, fx etc then you want ableton, but if you're just straight beatmatching house or techno or jungle or whatever and you have the tracks prepared then why not just do it live with traktor or something similar? no dj should be worrying beatmatching these days! its all done for you. i think its great because you've got all that extra time to concentrate more on selection, hard and fast choppage, long blends etc.
i went from vinyl to torque-plus decks (this was pretty crap) to ableton then finally virtual dj-plus little pioneer midi controller. i'm finally happy with my set-up. Uses very little space, sounds great and no more clangs!
like you i did a few mixes in ableton and though i was happy with the final results, it does kind of suck the life out of things (too much temptation to endlessy fiddle and fuss). my live mixes are much vibier