You will get different answers from different people.
I used 2.0 ohm boges on 510 batts for a few months. Finally got sick of chargins/rotating
batteries every 2 hours so I gave up on the 510 and went ego.
I wouldn't suggest anything lower than 2.0ohm though.
(btw: have started seeing starter kits with low res and dual
coils on simple 510 sticks, so it is definitely an option)