I do not have an LS10 so I can't say how good/bad it is, but from my experience with my CRT.5, it is a very good handling and tough truck/buggy. I am actually running 4s on it right now, and it is doing very well.
And with Mike's extended a-arms and chassis, it will be even better. There are also many more converted CRT.5's than LS10's (from what I have seen at least) so that may benefit you in deciding how to do the conversion and give you idea's for mounting electronics, etc.
EDIT: You happened to post before me, but the diffs in my CRT.5 are holding up fantastic. It uses a scaled down 1/8 diff, so they are very tough and should hold up to any power plant you decide to use.
