Outrunners and water?

[BP-Revo]

Alright...well, as some of you know, I'm looking to get a new E-Maxx so I can have a waterproof vehicle. At first I was going to leave it stock, but based one what the new Titans and waterproof EVX-2 fetch on eBay, I'm thinking of making it brushless...

I also want to try an outrunner setup, and I heard someone else mention using an AXI outrunner in their new E-Maxx on 20/38 gearing or something.

Now I think I want to do the same, but I don't want to lose the waterproof ability of the E, and thus will probably buy an MGM because they are waterproof. Now, my question is, how will the outrunner hold up?

Any comments?