I've got a uds with a weber lid and an old traeger with a flat top. I've never noticed stuff dripping on top if my meat in either one.
I think a box style makes for much more efficient use of rack space.
I also cook on my buddies offset made from a big air compressor tank, I think it is a terrible waste of space.
Silver UDS with weber lid, UDS #2 black with a weber lid, 1995 Treager pellet grill, 22.5 Weber