Had slight issue with left cleat clipping in when it was new. After a few weeks of break-in period, it
seems fine. It took a bit longer to mount/align cleats on my Sidi's than Look cleats. One other thing
to note is keep them clean of debris. A lot of people put dry lube/wax on cleats; some befor each ride.
Also, be sure to carry extra cleat screws with you on your rides.
I like the extra clearance on cornering, double-sided clip-in ability, and float.
Wanted to add my experience with Speedplay (not good). I originally started my biking with SPD clips and after using for a few years got talked into using Look Keo's ... they were ok but I would often screw up and try to use the "wrong" side as they lean backwards when in free position. I thought that the speedplay sounded great giving a wide area across the bottom of your foot to attach to the pedal to transfer the most energy into the pedals. I bought and had them put on in my local bike shop and went out for my first ride ... I got a few hundred feet and could not get my right foot snapped onto the pedal ... too tight! I started looking down and pulled right and went into the curb and went flying. Ended up breaking my collar bone.
If you are going to use the speedplay then you should have them setup properly (some shops do it with lasers to keep the planes in line) ... my foot was not fully "flat" and parallel with the pedal and needed shimming so that the shoe bottom would be flat with to the pedal.
I personally gave up and went back to SPD pedals as I could get into and out of them very easily without having to "think" about them.