Well, with our ultra-lite make & model TT, all loaded up for camping with just your ordinary stuff you'd have like sewer stuff, BBQ, kitchen dishes & utensils (including some food), clothing & bedding, etc., etc., we are about 200 lbs away from the GVWR. And that's with empty holding tanks and one battery.
The manufacturer's brochure says the NCC is 1563 lbs. Weighed the TT immediately after picking it up new from the dealer and then after doing some mods and after fully loading it up for camping and the additional weight after picking it up from the dealer was 674 lbs. The NCC is waay less than the manufacturer's figure - by 889 lbs. We did order a bunch of options and that *could* account for some of that, but the sticker on the outside still says 1563 lbs for NCC. If we travelled with just one full holding tank, we'd be over the GVWR. I wouldn't trust any factory CCC numbers.