RE: Durable, waterproof, tough bashers. Alternatives?
well as for waterproofing its a gimmick as the electronics might be, but the rest isn't
The metal WILL rust, and usually does it quite fast so after every run you get it wet you would have to hose it down with wd40 or some other penetrating oil, and blow out the water with a aircompressor or something.
I wouldn't worry too much about servos being waterproof unless you play submariner with it if you are really worried just put some liquid electric tape around where the plug leaves the casing, and around where the parts meet (most have 3 seams) you can also pack the gear area with grease to make it even more water tight. As for the receiver it can easily be made waterproof just slapping a traxxas waterproof box on it, or if it has a radio box just sealing it with some kind of sealant.
Some people also have taken the receivers apart, and coated it with corrosion X or liquid electrical tape (I've done the latter on an ESC, and a part I use to monitor voltages to great success)
The hongnor, and hoabo buggies might fit your bill like hongnor x1x, or hoabo hyper 7.