I've used Speedplay Frogs for a few years and wanted to move to road shoes & road pedals. I considered the Speedplay Zero, but ultimately chose these because they have the lightest disengagement mechanism of all Speedplay pedals (other than Frogs, which have zero). I love these. Clicking in is straightforward and the amount of float is perfect. Disengaging doesn't require too much force - I had knee surgery a year ago and can't withstand too much twisting of my knee. The plastic covers on the walkable cleats are great. I have yet to slip on concrete, tile, etc. So glad I bought these. The technical rep at Speedplay was a huge help for me selecting these - I called him multiple times! If anyone is considering Speedplay pedals, these are great. Speedplay does not recommend these for racing only as a CYA (Cover Your A...) statement. A very strong rider who is sprinting to the finish and has noisy feet might disengage. But other than that, you won't unexpectedly pop out of these.
Love the walkable cleats. I bought these to replace my stainless X2s which I also loved because of the float. I kept wearing out the cleats and thought this is a smarter approach.