I was rocking a big mish mash of the Magpul XTM and UTG rubbery ones on the sides and the Magpul ladders on the empty spots on the top and bottom. Just got in a set of the Kwikguard long covers for the sides and a couple of 3 packs of the Surefire ladders to fill in the empty spaces on the top, bottom, and sides.
Haven't mounted em up yet, but the Surefire ladders I got seem to actually have more bulk and shape than the Magpul (ERGO made I believe) to me. They seem a little wider, have a little scallop running down the middle that winds up flush w/ the rail and taper down to the rail on each side. They are also alot more flexy and maybe not quite as grippy but were way cheaper (pack of 3 14 space ladders were ~$15 on Amazon, Prime eligible). I'm thinking they'd be too floppy to use for my shell deflector add on, but seem like they'll work pretty well as rail covers.
Edit: After mounting them up on the rifle rather than the 45 deg adapter, the Surefire ladders are definitely lower profile than the Magpul ones. They look and feel pretty good though IMO and seem like they should protect the lips of the rails just as well.