Keep zone/cursor/timing etc... The more options the better.
Not everyone likes the same things.
Yes, but unlike other useless arguments, these both happen to be in the same department of development. So, this isn't a "mascots versus AI management" debate, this is a matter of time, memory, and other resources being consumed on both instead of just one.
I'm not saying that I'm for one hitting system, but I'm just saying that this is a time where they literally can only focus on one at a time instead of multitasking implementing features into a game.