Personally I think the left hand side lever is more compatible for aright hand shooter than is a right hand lever. The only side lever opener I have is a left hand one on a non-Shootable W Richard s hammer gun with Birmingham proofs, likely a Clabrough built gun. This was my late Grandfather's gun so I hang onto it.
In piking it up & handling it tough the left hand lever seems very convenient, I think if I had one in nice shootable condition which otherwise met my specs it could quickly become a favorite opening method for me. Your thumb is already across the stock so seems more natural to drop it down to that left lever than to cross it back over to a right hand one.
