ive got speedplays on two of my bikes and i love them.

my only problem with them is with sand/dirt. step down on some muck and the peddle is rendered pretty much useless. i couldnt feel that hard engaging click i normally do when my cleats are clean. so it's regular cleat maintenance for me. anytime my foot touches down on anything except asphalt/concrete, later that night i'm cleaning them out. hassle, but worth it for a solid pedal.

a buddy of mine has the icliqs and he loves them, keeps going on and on about how effortless it is to clip in (not the case with speedplays, for me anyway) and about how stable they feel.