I've been through a ton of them, and I can promise you that Nitro's are every bit as well built as any of the other leading brands. And are even better built than many.
I've chopped up a Champion, a couple of Chargers, a Triton, Tidecraft, and whatever the one was with the "Kevlar infused Incredible Hull" (name escapes me at the moment) with a chainsaw, and I was surprisingly disappointed in the frame and build quality. I'm not so sure that any of them truly deserve their reputation. Lots of little things that show a total lack of engineering knowledge. And a lack of structural integrity.