I have used em all,,,(thats what happens when you get old),,,bak in the 70-80"s there were many ranges that used the U shaped benches that you sat in the middle of and the right edge was close (for right handed shooters) so the port on the left side became in vogue,,,then ranges began constructing the little (cheaper to build) benches that you sit on either side of,,,then along came the mini port or bak to Right/Right,,,,I have stuk with the RB/LP thru it all ,,,especially since I shoot a lot of long range now ,and lots of those ranges use the old style U benches,,go figure,,,just remember ,,,slow is smooth ,and smooth is fast,,,,we are blessed with many great actions today with every port configuration there is,,,I like the RB/LP with the bigger cases that wont eject thru a mini port,,,( there is a Maxi port avail,,,) ,,,,Roger