The ending did work surprisingly well. I've had an amazingly hard time watching this show because I couldn't sympathize with its narcissistic characters. I didn't like a single one of them and I'm not entirely sure I was supposed to.
Nate was a bastard to the very end...man..what a bitter character he was...even in death he was cruel. At least they softened him up in the last 5 mins.
Ha, yes, I hear ya' on that last thing: I've often felt that the writers and creator of this Series intentionally offered up that which was repulsive to us viewers, that we were not intended to sympathize with most or even all of them at many critical points.
I remember having a similar conversation a while ago when "Lisa" character was first introduced and I said then (and correctly, given how things developed afterward) that Lisa was creepy, was the compromise, not someone we as audience were anticipated to care for well, easily or at all...and then look.
The Series DID make those challenges, you're right. It produced a love/hate response for me as viewer and I always ended up anticipating the next Episode, despite myself.