If you are posting about these:
eGo Mega Dual Coil Cartomizer Round Tip I too get about a week to 10 days out of them especially using a thick BWB juice.
Gotta ask - what battery do you use for them? I use a good ol' basic starter kit eGo and in no way does it give a "great finished look" since it is larger in circumference than the battery.
The clearomizers mentioned are also pretty good but I noticed after a few days they brown up a bit and look a little gross. Even if I use a light juice I get a ring of dark juice that settles to the bottom of that carto. I blow it out before a refill.