Alright, I just tried to start the game again and it worked. Seems a PC restart fixed whatever was going on.
And actually I was thinking being able to aim straight down could be useful even when standing normally. I found myself trying that when standing on ledges. It could also be used when you're hit by a little bug, so you don't have to run away to shoot them. I know it's just a little thing, but it would be nice to be able to do it.
I do enjoy the "character weight" thing, it makes actions more deliberate. And it really isn't too much. Cheers!