I just got my first mod in the mail today...a VV box mod from Foxy Box mods. The only thing I have right now that I can really use at 5v are some 3.0ohm cartomizers. I wanted to pick up a higher resistance atty and I read that 3.5 is a safe bet. Ikenvapes has 3.5ohm 306's and 510's. Anyone have experience with both of these? Opinion on which one is the better choice? I definitely prefer my 306 for LR but I was wondering about the higher ones.