I've noticed on some pictures of older Prodrive and Gatortrax hulls that there are knee braces running from the transom to the cross brace on the floor, but none of the newer boats seem to have them. I assume that everyone has deemed them unnecessary. Does anyone on here see a need for them now, or are the standard mud-hull transoms strong enough as-is?

Andy, I have dual knee braces on my boat and can say that they really lock the transom to the hull. No give or play in it what so ever. But seeing what these guys put there boats through jumping dams or what not with out them. hell its gotta be strong!
knee braces might just be an over kill. So far no stress cracks or anything still like the day I bought it over 2 years ago. I personnally would get them on every rig I'd buy. Duals though not single. Even if its an over kill. Might not go as big and maked sure there tied into the stringers. I like mine.