I bought a couple and have been in my rotation for about 3 days. So far, they seem to be performing better than any SR or LR cartomizer I have used to date.
They seem to be on par with an EVOD clearo, but not as good as a ProTank I/II. The flavor is not muted like other cartomizers I have tried. The vapor production and TH are what I expect with the juices I use. I have not used them long enough to have an opinion on longevity. There has been some gurgling, but a few moments of holding them upright seems to resolve the issue. I have experienced zero leaking, although I am using a UDCT.
I will definitely buy more. Aesthetically, I prefer the look of a cartotank. The cartomizers are what have kept me from using them as part of my rotation. This is no longer the case. Hopefully some find this helpful.