Once you find what your "sweet spots" are in terms of set voltage for each individual
juice that you have (and do keep track), you'll have a better idea of what resistance cartomizer or atomizer to order for future use.
Most fruit flavors tend to do better with normal or even lower voltage numbers. Tobacco and coffee flavors seem to taste better in the higher voltage range. Your own experience may vary.
If you find you are not
vaping any higher than say 4.4v, a 2.0 ohm carto might work best. Higher than that, a 2.5 ohm or higher resistance would probably be better. Just from my experience.
There's differences in cartomizers, too. I've not cared much for Boges, but when I ordered mine it happened to be around the beginning of Boge-gate and their quality control issues. I started with Smoktech dual coils and for a long time ordered those simply because they were what had come with the
tanks. I decided to try single coil Smokteks single coils with pre-drilled holes, and pretty much love them. Single coils provide me with the same vapor and flavor the dual coils did, but don't drain my batteries as bad. Not as much throat hit and not as warm, but I prefer a cooler, milder vape.
Single Coil XL Tank Cartomizer for the SmokTank XL
For those reasons, I've found that I don't care for dual coils. To me, they were a great idea that just did't pan out. I think Smoktech is benefiting from a lot of unknowing customers by promoting the dual coils and putting them in their new tanks. It seems there are a lot of people who have switched to the single coils once they have tried them.
Having said that about cartomizers, I probably would not like the V-max with its tendancy to produce higher voltage than it is set for for the same reasons.