I've been using the 808 cartomizers with 510 batteries (thanks to the adapters also from from HealthCabin) and far prefer them over the standard 510 atty/cart.
And since they work out to only about $2 a piece I don't feel guilty for tossing one in the circular file after 3 or 4 days.
Also, they shorten the size of the whole cigarette to just less than 100mm with a standard 510 battery which I can use with the 510 PCC.
There have been a few cartomizers which are a little harder to draw on because the adhesive wrap is shifted slightly... but only 1 of the 30 some odd cartomizers I've used has actually been useless. Overall I'd say that's a pretty good record.
Phil