It seems theMSR Coyote is ubiquitous. However the SMC snow picket has a couple of refeinements on the design which makes it preferable IMHO.
The stroke of genious is that it is sharp at one end and blunt at the other. Think about it. When do you need to hit the picket on both ends? Or drive both ends into the snow. The Coyote has two kind of sharp ends, effectively one not very sharp end and one end that's not too easy to hit with a tool. With the SMC the sharp end goes in the snow when you hit the blunt end. Duh.
Like many great ideas it's so simple I don't know why nobody thought of it before. There is no great loss that it is not reversible since you're unlikely to mangle the sharp end enough to make it as blunt as a Coyote in the first place. Sooner or later with a Coyote someone drives it in by hitting the designated "sharp end" and screws it up. This can't happen with the SMC.
In short the SMC snow picket is easier to place and generally lasts longer than other pickets.