I have a set of Butler Creeks without the plastic lens. At least I have a front one. I took off the rear one when I got busted in the eye since it sticks back an inch behind the scope. When carrying the rifle slung over my shoulder, the rear one isn't needed anyway.
The front one does give good protection and it's very easy to use in the field. However, it will trap moisture and a little fogging on the front scope lens is very possible on a wet day. I've considered drilling a couple small holes in the side to let it breathe but I don't know if that would solve it without killing the reason for the cover in the 1st place.
