I use FS2 and Traktor 3

Traktor 3 is excellent, and the main reason I went with FS2. I don't scratch so wasn't that bothered about lightning response times, and I can't notice the difference when mixing.

FS2 is stable, hard wearing and pretty solid.

But - its one more thing to go wrong, and you need a bit of time and space to setup. Its not difficult, but I challenge you not to crap yourself a little bit when you have to unplug the decks from the dj before you, plug them into FS, boot up traktor and pray that the timecode locks on for you.

9 out of 10 times its fine - but there's always a worry - maybe the needles are rubbish, or the tone arm has been wired in wrong (happens) or a cable has been L/R inverted or similar.

And no matter what the dj system - all of them require that you plug the deck directly into the unit to read the timecode directly, then back out into the mixer. A lot can go wrong in between, and troubleshooting before you play is a nightmare.

The older contendors (rane and FS2) are well road tested, upgraded and well used. I'd be more inclined to go with the established players than the challengers, who are yet to prove their mettle and more importantly their stability.