What are you going to use on the 5v passthrough? If you plan to use cartos, even the regular resistant were too low for me. It's very powerful, I got sick for a day and it was recommended that I go to high resistant cartos (around 3.0 ohm). I still couldn't handle it, I am happy at 3.7 volts.
Some people are really happy with the 1.5 ohm dual coil cartos on 5v. I never tried it, even though I had both (too afraid of getting sick again and I didn't have any juice at the time lower than 18 mg).