I don't think that people who play with single or double foot pedals are necessarily more talented than the other. I will say that personally I think it takes more time and effort to double with you left foot than your right foot, if you RH and vice versa. Whichever foot you use the most is obviously going to be faster than the other. But I give people who can double with both feet props cuz I can't do that real well. I am real good with my right foot, but with the left I am "garbage", meaning I can just do single beats. I guess with practice, anyone can play well with both feet and just in case one foot get broken or something, you always got the other foot as backup.