We had a 5b for a while. It was fun, but you really need wide open spaces and you'd be surprised at how easy it was to get stuck. I suppose that we were doing things that it wasn't designed to do. As far as the weight goes, it was also surprisingly light, once the engine was removed. I just never really thought that an XL would be enough to push that thing around.

Mike, what are you thinking in an XL? Perhaps a sub 1000kv motor? I'm starting to get bored with what I have and want to build something new. I was going to do a Serpent, but don't know what I'd do with it once it's done.