markg, I'm happy with my switch from SPD to Look Keo. The biggest difference I found was greater lateral stability out of the saddle, which is helping me stay out of the saddle for longer stretches of time on steep sections. Well, that and much faster cleat wear. I also have a bit more trouble clipping in, but it's not that bad, and I'm getting better at it. If it matters to you, I hear Shimano road pedals/cleats have much slower cleat wear.
herbm, hope you like your new wheels.