I used Quattro's for 18 months and never had a problem with them. Simple mechanism, easy to clip in and out. Nearly impossible to jam either way. Before that I had looks, and just popped out of them one too many times for my own personal taste.

The only reason I ditched the quattros recently was because I've been doing some PT as a result of a crash back in February, and I'd been getting hot spots for the past month. I wound up switching to SPD-SL's (ultegra 6620s) and they've got a really great platform but are a little more difficult to clip out of (very stiff binding, even on the easiest tension release).

As for speedplays, meh. While they seem like a decent idea for the float, I've seen too many people fight to clip in after they get their cleats clumped with dirt for my tastes.