Have you had good experience with your 4081? I was thinking about buying one but was told how much better 510s are. If it gives decent throat hit then that's all I care about. I don't need to be completely engulfed in vapor.
I'm one of the few here that swear by the 4081. I travel extensively, and the unit is small, and easy to carry. The battery issue is an on going thing. My vaping style is similar to analog use. I vape when the desire arises, which is once an hour or so.
When the need arises, I take a break, and take 5 to 10 puffs over a period of about 10 minutes, just like an analog. My batteries last all day, from about 7:00am to about 5:00pm. I use my passthrough when I on the puter.
If you plan on vaping constantly, the mini's won't impress you. You'll need a heavy duty mod for the extended battery life.
Throat hit? Definately! The 4081 and the M401 give great hits. They also have smaller carts, which will need refilling more often than the mods.