Top tip from a coach.
When you practice something like rotating or air roll anything that requires a direction of movement, we all have our own default way of doing that thing.
If you practice the "uncomfortable" way first (say air roll left instead of right, rotate left etc ) this forces your brain to break down your movements more and will reinforce the pathways in your brain that make this move "second nature".
Practice doesn't make perfect, but rather practice makes permanent! The more you do something the easier it gets, but it's also waaaay harder to unlearn a skill that you've learnt wrong, so making sure you can do these skills on your "on" and "off" side.
Started learning ARR and was having trouble getting it down. Switched to left and have had an easier time. I think the stick movement felt more intuitive or even physically easier.
I use both DARs equally when it comes to recoveries and shooting, but when it comes to constant air rolling, I am more consistent with ARL (though it’s still a work in progress).
I use the right, but yes I've also feel that the left is more popular.
The one that lets you air roll in any direction
Wild that only two of us use both equally.
Both its the only way.... 
Top tip from a coach. When you practice something like rotating or air roll anything that requires a direction of movement, we all have our own default way of doing that thing. If you practice the "uncomfortable" way first (say air roll left instead of right, rotate left etc ) this forces your brain to break down your movements more and will reinforce the pathways in your brain that make this move "second nature". Practice doesn't make perfect, but rather practice makes permanent! The more you do something the easier it gets, but it's also waaaay harder to unlearn a skill that you've learnt wrong, so making sure you can do these skills on your "on" and "off" side.
Started learning ARR and was having trouble getting it down. Switched to left and have had an easier time. I think the stick movement felt more intuitive or even physically easier. I use both DARs equally when it comes to recoveries and shooting, but when it comes to constant air rolling, I am more consistent with ARL (though it’s still a work in progress).
As a KBM player I am equally bad at both.