A lot of the whining is from the classic gitless gudless. But there is some truly bad balancing. Such as the Carthus warriors able to tank two, two handed ultra greatsword r1s before staggering. Which makes them badass as fuck, but utterly broken with how fast they are.
Or how many bosses and enemies have frame zero attacks where you take damage instantly. Like Godskin Nobles blackflame belly but faster and more damage. There's also the matter of extremely low soul gain from enemies and bosses.
That said (and not addressing actual bugs like cleric beast reskins range attack being undodgeable), I still adore this mod. Where they've failed in balance, the team has made up for thousandfold with how beautiful the world is.