I'm the original poster of this review. It seems too much time has passed for me to edit it - but because this review still gets a lot of views, likes, and comments I thought I'd share my impressions 4 months after the fact.
1. Airflow and taste
Airflow has a significant effect on how much flavor you get out of this device, and airflow is also a common point of contention for Protanks. I don't think I worded this well in my original post, but the 'beauty ring' that comes with the device is an important component. The ring itself has no air inlets at all; if you put a flush mounted carto tank on the protank beauty ring, it would be completely sealed. Using the protank on a mod that has its own air inlets, without this ring, means it's going to be airy. Kanger only makes ego style batteries, and the beauty ring on ego threads + protank on an ego battery has a much tighter draw than putting it on a 510 mod without the ring. Also, when you do this, you can tighten or loosen the ring itself to adjust the airflow.
2. Epoxy and heat
There are two series of Protank 1s (sunvapers has an interesting teardown.) In the original run, the metal end caps at the top and bottom are attached to the glass with glue. Over time, this seal can break (a cause of leaks and other performance issues). I do believe that protanks can degrade over time because of this, and even if the caps don't detach from the glass they lose their air-tightness.
3. Metallic taste
I do not use my original protanks anymore. They taste metallic to me. They did not taste this way when I first got them. Some people have suggested putting a piece of rubber over the tip, however I don't think the problem is the metal in your mouth as much as the device itself imparting a metallic taste on the liquid. The insides are not stainless steel, but plated brass, and I think over time it starts to make the
juice taste like crap.
Whether or not you notice this depends on your
juice, your sensitivity, and whether or not I'm crazy.
4. Dry hits and gurgling
I vape max VG juices, and I didn't get any gurgling until the tanks started to lose their airtightness, at which point you can't do much about it. If it's gurgling right out of the box, that's probably not your issue.
Like all the Kanger BCC products, wicking is going to depend on your juice thickness. If you're getting dry hits (more likely with thicker juices) removing a single flavor wick can be effective. If you're getting gurgles not related to the above - I don't think any BCC is well suited for high-PG ratio juice.
One more cause of gurgling out of the box on any kanger is that your head is not completely screwed down into the base itself.
Another dry hit solution - unless your liquid is very thin, I wouldn't over tighten the base of any bcc because it will choke the wicks. For my juices I tend to leave about a fingernail's worth of space when tightening the base (be it a protank, evod, whatever...)
