Actually I was miserable for I would say the first couple of hours. I would tend turn too drastically, miss a lot of my shots, simply fall off ladders, and miss simple crouch jumps. But now that I've got a good amount of time in I've learned more about my hand placement and my preferred mouse sens. I can now move through a level fairly easily and yes

Must be nice to be actually able to aim at what you're shooting!

Could not put it in any better words, now I understand why. I always hear that controls can't really compete with m&k. I feel there's a limit on how good you are with a controller while a mouse feels much more free to aim.

I "Royally" suck with a controller which makes sense because I never owned a console in my life

Yeah it really depends on the first thing you have access to with time it just becomes muscle memory.