If your happy, whats the point of change?
Possible if you are after a slight bit more power and vapor (at a cost though) consider a KR808D-1 battery on a 510 carto.
Battery is up a solid 1/2v and is the same difference as using low resistance 510 carto's. The KR
batteries , however will last a little longer before recharge.
It takes an adapter (about $3 to 5.oo, US) since the connections are opposite.
pig
(wow, people let this one sit for 5+ days?)