I have a variety of plates ranging from cheap generics to RRS, original Arca-Swiss, and one nice custom plate for Sinar. They all work, and cheap generic plates are satisfactory for many uses. RRS plates tend to be designed to be as light as possible and are made of excellent materials, but it's not as if they're that much lighter than a generic plate without cutouts that remove a few grams here and there. Some RRS, Kirk, and other plates are designed with ridges to keep the plate from twisting, and there are L-plates to mount the camera horizontally or vertically, and the ability to slide the camera fore and aft can be useful with large cameras or long lenses. There are also A-S style replacement feet for long lenses to give the lens a lower profile on the head.
For flatbed field cameras, I think you want the RRS B35 plate, if I remember correctly. It has a larger surface that contacts the camera bed and a relatively low profile.
On my Linhof Tech V I have a 2" generic plate on the body and a 4" generic plate on the bed, and with a long clamp I can slide the camera from one clamp to the other and use them like an ersatz macro rail in the field or balance the camera wherever it makes sense to do so.
Clamps are another issue. Screw clamps will usually work with all plates. Lever/cam-locking clamps are quick to use, but not as universal. They don't close tightly enough for some clamps, and that usually includes the rail on an actual Arca-Swiss monorail camera, even though that is theoretically the standard.
Also note that with some cameras it makes more sense to set up the plate along the left-right axis (which favors use with a ballhead) and with others it makes more sense to set up the plate so the camera slides fore-aft, and then there are square plates that can clamp in either orientation.
Since I use an Arca-Swiss B2 head, I have all my clamps set up in the fore-aft orientation, but that means that I can't use an L-clamp on my 35mm cameras, at least not with the B2.
My Stroboframe Pro-RL also has an Arca-Swiss style base, so it doesn't require and additional clamp to mount it to an A-S style clamp.