Not sure if this is what you mean, but I don't like the 2 health bars. If doors are precious, we should be able to keep them alive through more welding like before, it'd make support's welding bonuses very nice. I think.
Well... I think the fact that when doors get destroyed and they STAY destroyed is a great feature.
I just don't like that doors don't even last at all. There's next to no reason to use them outside of buying a small delay when you're kiting. And even that's no good because the bloody zeds are going to respawn in front of you anyway.
Welding used to be the bread-n-butter of holdouts in KF1. Now it's useless.
Unless you consider standing in a circle in a wide-open area a holdout.