Hi pmos69
The BMF auto battery can't be beat, for all the kits I have tried atleast, and I have tried a lot!

The M602C, is my current favorite, the PCC is outstanding, it holds:
1 - Assymbled
ecig
1 - Battery in the charge slot
3 - Cartomizers WITH the condom ON
put it in your pocket like you did your pack of cigarettes, and you are good for atleast a day.
The M602C cartomizers seem to perform as good as the BMF cartomizers, and I think the design while different is very good as well. They took measures to prevent burning.
If I were forced to get rid of everything except for 1 kit, right now I would keep the M602C kit. Granted the auto switch is not as good, but it makes up for it 10 fold in the other areas.
edit: I also just ordered some cartomizers from ............., if they are the same as the ones I got in my Black Cherry kit, I will be happy. and for just over 4$ for a pack of 5, is a deal.
And to show just how much I liked the Black Cherry M602C kit, I ordered 2 more as spares. Their deal right now is 2 for 100$, minus the ECF1 discount code of 10%, and it came to 90$ which shipping was free. Not bad at all.