Are you talking about the '03 bikes?
I've got an '03 Escape 8.2 and I reckon it's pretty damn good. I bought a 17.5" frame which is a good fit for my height (6'1") even with a short stem. Personally I wouldn't get one any bigger though. The frame is pretty beefy as you've probably already seen so hopefully it should hold up to a bit of abuse. I ride mainly technical trails with drops, logs, rocks etc., a bit of DJ and the occasional urban ride and the bike is great for this kind of stuff.
The only thing I hated about this bike was the stock pedals. In the wet they were slipperier than greased owl s**t and the bearings were crap right from the start. Last week I bent the Formula rear hub too but I don't think these come on the 8.3.
I haven't really spent that much time on GT hardtails (only ridden a mates GT a few times) so I'm not sure how it would compare to your Ruckus.