As Rys said, I also prefer reverse shift, It's mainly for the track with the increased lean angles. Not so much for changing down, that should be done before lean angle occurs but on exit. Imagine left turn, cranked over needing to hook another gear on the way out. Which would you rather, try to get yr toe under the lever to hook next gear or just tap it on top? Similar on right turns when yr off the bike, left leg's in effect shorter and it's easier to attack the gear lever from the top as opposed to trying to slide it underneath.