I don't mind the idea of the fight and harder 4 player content but I absolutely despise the overuse and reliance on one-shot mechanics for nearly everything.

Make a big mistake, your dead
Make a mistake, your dead
Make a teeny tiny mistake, your dead
Don't make a mistake but the person next to you does, your dead
Nobody makes a mistake but has a less than perfect latency... ooohhhh your SOOOO dead

There has to be other ways to punish players for mistakes besides off with their head...