Everyone I know who switched wondered why they hadn't done it before, and all feel it's not only easier on the knees, but are getting more power to the pedal.

I only know one guy using clips now, and he uses 3 straps on each foot.

I train/recreate on Looks with some float, no problems. I tri on Looks locked in. My knees ache the next day, but it's worth it to maintain a relentless pace for 15m or so.