I am looking to get QR plates for my new 7D and my 100-400. Looking at the prices, I can get a RRS or Kirk plate for about 60 bucks each or generic Arca Swiss QR plates off EBay for 8 bucks each.
Now I know the general adage that you get what you pay for, but that is what I would like to objectively know. Do the RRS or Kirk plates fit the clamps better, or do they last longer, or are they custom designed for the camera and lens to fit better, ormachined better and won't ruin the camera or lens finish, or what? I know that the RRS plates for examples have other things like lugs for attaching straps which presumably require more machining, and have other intangibles like being US made.
Bottom line is, what is the $40+ premium getting me with RRS or Kirk?