Can't comment on Robbins, but I can comment on Crown, as I've got one. It was
cheap, and it kinda shows. It's not dead straight, the windows look kinda
glued on (their welded actually). Didn't come with enough snaps, and they
weren't the right type. The section of snaps that go around the top frame
can't, they aren't even close on the rearmost ones. After waiting weeks, I've
come to admit the top will never smooth out on back. It has more straps and
flaps then I could ever figure out. No instructions.
There are good points though, The vinyl itself is good, the cloth backing under
it is also good. The plastic windows are of good quality. The price is good
($115, shipping included).
Would I buy one again? Probably not.