After reading some of the posts here, I decided to order a couple of pro tanks from canvape.  I have never really been a big fan of bottom coil tanks in the past, but thought I would give these a try and see for myself what the hype was all about.  Well they arrived this morning and my first thoughts are impressive.  One of the cons I read was the drip tip is not interchangeable, true but, the drip tip is very comfortable.  I haven't had any issues with leaking or gurgling, I have also read that you need to keep a juice level of 1/3 or better.  I am very pleased with the good solid vapor production even at lower voltage.  I have not experienced any loss in flavor, in fact I find it to be better than my vivi nova's.  I make my own vg juice, so it is thicker than a pg/vg mix.  I would also agree with an earlier post that fruit flavor juices need a lower voltage and dessert flavor juices need a little high voltage.  Also pleased with the fact that the pro tank comes with a cone to stream the look when using a twist battery.  Another big bonus is the price of the replacement coils, very affordable.  The pro tank is a juice hog but I guess that's the price of good vapor production.  I like the pro tank so much that I ordered two more today.  I guess I'm a bottom coil fan now.