this one is hard for me, I have conflicting reviews I am not sure if it is a batch issue or not, I should just bite the bullet and order some. I will soon I think.
The conflicting reviews are accurate. The BCC heads need to be adjusted to your juice thickness. There are 2-3 thin flavor wicks on top of the main coil. Depending on your juice thickness, some of them need to be removed. I do this when the heads are fresh out of the pack.
Some people have posted about having trouble getting the heads apart. The trick is to hold the base firm and rock the top. It'll pop right off. Pulling on the top will get you nowhere.
Ideally, I would like something that requires "zero setup" but removing the flavor wicks is so easy and simple I'm happy to do it. I'm getting the best vape of my life off these and I've tried a lot of equipment. I'm even finding that I like juices that I didn't like previously on other equipment.
The BCC may not be for everyone given the setup required but you carry other other things that require fiddling, and unlike most vendors you warn customers that they may have to do some fiddling.
I'm seeing the BCC Mega at a lot of other vendors lately. What I have not seen is a NON-Mega BCC. Does it exist? It would be interesting to inquire if/when you order. I only fill my BBC's 1/2 way because it lasts me through the day and then some. A shorter non-Mega BCC would be awesome.
I'm looking to buy 5-10 black/black BCC's. You wouldn't get stuck with many if you kept your initial order small and stuck to black/black.

I'd also buy a few packs of heads, higher ohms preferred.
DISCLAIMER: I vape on a VV device. These may be a total fail on non-VV devices.