I rarely use my tach , which is making me think about going to one with a playback mode. That way I can see what rpm`s I`m shifting at and going through the eyes at. Definitely slows the car down to shift (`Glide) into high by the redline .At launch I use my MSD launch RPM module set for 5400 and I can feel where peek torque is and shift there. Works every time .02 consistency !
chryco