I'm not sure how much is lost from the side cover removal, it's on an angle so a decent amount I'm sure.

If you installed the transgo shift kit as the instructions said to you're basically going to notice that shifts won't get slow when warmed up like they used to, normal up shifts stay pretty much the same. Now downshifts 1/2 throttle and under were hugely improved in my case. They were very slow before but now just as fast as an up shift.