It's a great set, and I don't remember any structural weakness at all.
Even the treads, which seem like they would be boring and repetitive, were fun to me, though I can't really explain that. *wacko*
All in all, a fine set for building and displaying. I'm not convinced it's really great for rolling around, that isn't something I've tried. As suggested earlier, I did a 'Purchase of the Droids' scene and left it at that, and I'm quite pleased.
That said, if you don't own the UCS Imperial Star Destroyer, I'd buy it first. Clearly, it's a better deal with the current discount, and more likely to disappear sooner.
Just don't miss out on the Sandcrawler either, it really is a nice set (and the later ones apparently come with a darker coloured C-3P0 than the standard one, which is something I wish I had instead of the original one).