If you are used to the GMT800, I would say you may not like the GMT400. At least I didn't, going from an 800, then buying a 400.
They each have issues, of course. But the things I really dislike on the previous generation are:
Busted dashes,
Mediocre door hinges that cause the driver's side door to sag, then it binds and you break the handles,
Vortec engines with the goofy spider injectors,
Intake manifold gaskets leak,
Rear drums are woefully inadequate on the 1500s. I've got a buddy that says drum breaks are for losers (he's a young kid...go figure.),
ACs are kinda weak and the compressors don't last,
I've learned to hate distributors because they wear out and have left me stranded a few times.
I've got a 2000 K3500 and in addition on the 8 lug, the brakes are a nightmare to replace. The rotors are not a slide-out design. You have to press out the rotors from the hubs AFTER removing them off the truck.
A while back my brother's BIL was looking for an old Chevy and we even did a comparison. It's for trucks, but there's plenty of information on suvs well. Here:
https://www.performancetrucks.net/f...neral-discussion-130/gmt400-vs-gmt800-560602/
An LS-swapped OBS would be a cool truck tho.