Damn, I really don't have any of the issues with this you guys seem to have with it--this is the greatest thing I've ever seen and unironically my favorite companion ending by a MILE.
For those who are dissatisfied but are only going off of the patch notes, I encourage you to spoil the ending for yourself:
HAVING SAID THAT. There are solidly two schools of complaints I see with Karlach's quest/ending. Yes, I'm still a little miffed that I have a million infernal iron and nothing to do with it, or that her quest itself is still extremely linear and doesn't really have room for choices. But in terms of working with what's already there?? And getting us this ending in such a short time? I'm beyond satisfied. Sure, we can cross our fingers for an upper city heart repair in a Definitive Edition, but for now, I'm MORE than happy with
this extraordinarily cheesy epilogue of killing imps with my 7 foot-tall devil wife while a heavy metal cover of Down By The River plays in the background. Seriously, if I wanted my Tav to have a peaceful life on a farm with some kids, I would have romanced Shadowheart.