Ok, so what is the difference exactly?
Why #80450 is cheaper than #80750?

And next question is:
Which combination will be faster?
x11 9,5turn + #80750
or
x11 9,5turn + #80450
or
x11 9,5turn + #80400

Or maybe there won't be any difference in speed and acceleration but i don't believe in that. Common situation is in brushed world.

Regards