It’s going to change the length of throw at the pedal. If you like a real “short” pedal (applies quickly and rapidly) put it at the bottom. If you like a “long” pedal (more travel) put it at the top. Since it’s easy to change try it both ways back to back and see what you like. I’m most comfortable with a very short pedal but I’ve got a buddy who likes his the other way. I can’t hardly drive his kart. It just seems as though you push and push and push then they finaly grab.
Placement will effect the needed pressure but it’s very little and I’d be surprised if you’d even noticed the difference.