I have a PTII, a PTII mini and an Aerotank (couldn't find just the base in stock and was impatient). I have had zero leaking issues with any of the set ups except for some condensation on the battery post and the occasional drop of juice on the post. I apparently have the new coil version which has the silicon gromet instead of the rubber and the knurled stem (or chimney).
Sun Vapors has new PTII coils for $5.97 which is pretty cheap.
Personally, I prefer the PTII with the PTII coil and the Aerotank base...........even more than the Aerotank as sold with the dual coils. Don't know why, I just like it better. Everything seems to be inter-changeable and you could get the same effect on the PTII by putting your finger over one of the air holes located on the base on the outside. Covering a hole or two will give you the same "effect" as the Aerotank to try. Just don't cover all the holes.
Keep an eye out for "generic" heads because most who have issues usually state that they don't have true Kanger heads with it. I read a lot of people with issues and these are all that I use anymore and I have not had one problem at all.