Rapid rise was fine once you were used to it, until you wanted to rent a bike, ride a road bike etc. i never saw any shops running it on a demo bike, you would pretty much guarantee the rider wouldn’t have fun and thus wouldn’t buy the bike.
i would tell you to drive on the left if there was any research saying it was better, but no one has come up with even any theoretical advantages for it, let alone real world data saying it is better. Also, switching from driving on the left to driving on the right is much easier than switch between rapid rise and normal shifters.