Well, I'm glad to have found this thread. I've purchased several of the blank 4081 cartos from AZ Smoke Free and so far I haven't been impressed. Unfortunately I'll have another 17 of them to sort through and determine if they are worth anything.
Starting off now, 2 out of 3 went completely bad, and the 3rd one is hitting poorly (although it's completely full).
I'm using an automatic NJOY NPRO (meh).
Thanks for posting this thread, and thanks to everyone else who shared some insight into a good supplier!
Edit: By bad, I mean I will draw on the PV and the LED light comes on and stays on (even with no draw). I'm not sure if that's user error, or just poor mfg.