Thanks for the info and I'll keep an eye out on the mega platinum series or maybe sign up for stock notification and give them a try.
As for the 801 fusions, I've heard nothing but good things about those cartos in the forum and other reviews. If they made a 501/801 adapter that was either flanged or as wide as the drip well on my Provari so that my tanks couldn't slide down over the adapter, I would be more inclined to give them a try. Since the difference between 801 and 510 really is just the connector, I'm hoping that they expand the fusion line to include a 510 connector product as well so we won't need adapters.
i think the diamond series is supposed to be the 510 version of the fusion tbh, they work amazingly well, generally though i don't use them in tanks because of the same reason, they give you that gap from the flange to the tank, so i understand, but i generally use them around the house when i don't feel like dripping, and if there is a tank involved, i just don't care at my house lol.