What brand of cartos do you use, Baditude?
I started using the Ikenvape brand a couple of months ago. These are the Platinum Punched (a 2.5 ohm). They are superior to anything that I have used thus far. They provide the best flavor production, are longer lasting (2-3 tankfulls longer), and relatively fast filling. Never had a dud yet until I tried my first Fusion.
https://www.ikenvape.com/SearchResults.asp?Cat=1860
I use the fill from the top method of filling cartos, with a wooden toothpick in the center airhole to keep liquids out. However, I'm starting to inject my liquid with a fine needle into the top of the carto, between the polyfill and carto edge. This seems to work a little faster than dripping onto the poly while spinning it, and seems to work better for the more tightly packed cartomizers.
I recently got a batch of of their "premiere" 801-thread Fusions just to try them out. The 801's require an adaptor to use them. The first one was terrible, so harsh that it was unvapable; resistance checked ok, but probably a dud. I've been vaping on the second one for a couple of days now and it is quite similar to the Platinums. No idea what the difference between the Plats and Fusions are, but Ikenvape just introduced a 510-thread Fusion. The problem with Ikenvape is they seem to be frequently out-of-stock.
For my backup cartos, I use the Smoktek single coil, 3.0 ohm with either one or two holes. I started using these way back after being unsatisfied with the dual coil tank replacements. A nice carto, occassional duds. These are currently out-of-stock, too. Luckily I have a couple of months' worth of cartos in my stash of supplies.
Single Coil XL Tank Cartomizer for the SmokTank XL
Not been a fan of the Boge's, but I have to admit that when I tried some was during the Bogegate era. Slow filling, slow wicking, occassional burnt taste or harsh vapor. Occasional duds. The ones that I used were unpunched, and I am not a fan of punching my own.
Additional comment:
When I got my first mod several months ago, a Silver Bullet, I got some of these huge dual coils with it.
http://altsmoke.com/dual-coil-510-stainless-steel-black-xxxxl-carotmizer.html
These hold between 4-5ml of juice. At the time I thought they were pretty nice, although they did like frequent top-offs for best results. I recall they had nice flavor production and made plumes of vapor. I stopped buying them once I got into cartotanks. I recently found an unused one in my stash of supplies and am looking forward to trying it on the Provari once my shipment of cinnamon flavored e-juice arrives. I'm thinking this might be a great flavor to try with these dual coils.