Xfire was my first messenger ever I believe. I don't think I ever uninstalled it from my old computer. Although moving to this one, I miss the old Xfire skin they stopped supporting. Why they'd just drop the MAIN Xfire skin support and make a new skin is beyond me. I mean, the fact we have the option to use the old skin feels weird.
Anyway, Xfire detects games for you. Steam doesn't. Steam has problems with some people who use 64-Bit Java with their Minecraft (including me). I mean overall, of course Steam beats out Xfire. But that's because of Steam's base, Valve and all that. Buying games through it. Shouldn't mean Xfire is bad. Just not a big ass thing.