I prefer L1/R1 because it's traditional, and has been the norm on PS1/2/3. I honestly don't know why games are forcing L2/R2. Not only is it traditional, in some games it's just unconventional. If you're driving, you need to use the triggers for speed control, not shooting. It is really annoying that many games don't allow remapping buttons, and it's easy to forget to switch back when remapping them manually.
Also, do you hold your controller with four fingers on all triggers/bumpers or just move your pointer finger to hit them both?
Edit: If you vote and don't bump, I dislike you.