I've just poked past level 80 and I can safely say that I've only encountered a very small set of irrelevant bugs, nothing 'GAME BREAKING REFUND ME NOW PLS'.
One is misplaced quest markers, one is very rarely a horde boss spawns below the world and I cannot kill it, and the last being that maybe 1 of every 10 times I repair an item, it doesn't take for reasons I don't know.