I just had a commuter built up and my mechanic was pushing Eggbeaters. I was leery because I ride Speedplay X2s on my roadie, and I love the float and most of all the effortless unclipping.

I've used the mountain and road SPDs, and with both I felt like I was damaging my knee while unclipping. Even on the lowest tension setting.

Anyway, I was down to Frogs and Eggbeaters, and decided I'd listen to my mechanic because I could return the pedals if I didn't like them. The verdict after not many rides is that they are very easy to unclip from and I like that the cleat is super small--I think the Frogs cleat is a bit bigger and sometimes you need to trim your soles to get them to fit/work properly.