I've been using tanks for several months now, and am very consistent with my filling (exactly done as per SnowDragon's video), and pay attention to when they start to clog/gurgle. The paperclip trick gets me a little more time to hopefully vape enough out of the tank so I don't have to drain it when swapping cartos, but if so no biggie. I've gotten to where I can replace, refill, and prime a tank in a matter of a couple minutes tops. I just did 3 in 5 minutes this morning.
Having said that, I've probably gone through about 20 or 30 of these replacement cartos now, and once I discount the initial failures due to learning, out of the last 20 I have had 2 or 3 that failed during the first tankful, and I'm fairly confident I was consistent with my filling / priming / waiting on those... I ordered a ton of them on sale, so for what they cost me, the failure rate is acceptable.