Hardcore is anything but anymore. I find it all too common to be shot myself on guys that I get the drop on and wound down to ~40% or less health. Honestly it feels a lot like regular mode. I wonder where we deviated from the principle of shooting someone 2-3 times generally meant they were dead.
Team balance. Not necessarily balancing skill but balancing the number of people on a team. I don't see how this isn't built into the game. It gets rather sick having a game where the match seems even when in fact the bottom half of the team is nothing more than a revolving door of people joining and leaving. Boot people from the other team to the one without any people and call it even. Plus I don't know how many times I've been playing and getting stomped only to see that it's 10-5 or something odd like that.