Matt E.wrote a review of Speedplay Zero Aero Walkable Cleats on January 30, 2018
Familiarity: I've put it through the wringer
Like pretty much everyone I suspect who uses the Zero cleats and has to put down their foot a lot due to lights/stops and then pushes off a bit to get going my only gripe with them was wearing off the metal and screws and having to purchase a whole new set of cleats because of one area of damage.
These seemed a perfect antidote. Carrying around the plugs was never something I was going to do; so I have no comment on them. My experience with the yellow surrounding shield parallels all the negative comments on this review thread. They squeaked on climbs and the one on the 'push off' foot disappeared on the second ride.
So why would I cheerfully by these cleats again? Because even w/o the bumper feature they're a big improvement. Discarding the bumpers gives you a lower profile cleat so you CAN walk more easily, not well, but better than the older design. But the main reason to pay extra for these is that the steel cover plate is MUCH tougher than the 'standard' version and its shape does a much better job of protecting the screws. Regardless of the bumper feature, for an extra $15 this are a better value.