Here are a few things I have learned about the Kanger Protank after one month of daily vaping and consulting with other Protank owners on the eCig forums:
The flavor gets better once the atty has soaked for a few hours, the vaping gets better, (less airy) after a day or so.
Atty's will last two weeks or more with a well made, somewhat balanced VG/PG mix, (20 percent either way), if your mix has a lot of water in it, it won't vape well, (some vendors cut thier cheap VG with distilled water).
Dark thick caramel juices are touch and go, low voltage and the atty's foul earlier.
Rinsing the atty if it seems to be loosing flavor works well, run hot water through the atty, (hold it in the hot water stream switching ends), dab, (blot) wicks and let dry overnight or at least a few hours, flavor will be very muted if atty is damp at first.
Most of the burnt hit problem seems to come from screwing the tank down too tight on the battery, this twists the atty which in turn twists the wicks and warps them out of place, it can even twist the coil, so do not over tighten to try and reduce the airy draw. This was my first NOOB error.
Most leaking problems come from not tightening the atty each and every time you open the tank, even the first time you fill it, tweak it to make sure it is fully seated.
Gurgling can be caused by a loose atty, quick temperature changes as well as a tendancy to flood immediately after filling. I remove the tank from the battery, blow gently though the 510 end while holding a pipe cleaner in the stem piece just at the opening of the atomizer stem, (do not insert into atty stem itself, just cover the opening). This flushes out the liquid quickly and neatly.
Also, these tanks like to run hot, this also prevents fluid collecting in the atty stem and creating gurgling. 4.2 volts is just about right for the 2.5 atty, (depending on what your juice can take).
If you get a burned flavor, turn down the heat and vape until the burned taste is gone, if you leave the burned atty taste in the juice the whole batch will taste burned by morning.
That's all I know 'til I learn some more!
Update July 11, 2013: The Vapor Lady Lounge Store is now open! Drop by and check it out!