Personally I'm still on a never-ending search for the perfect carto. So far 510 Boge has been tops, although the best Boge is only good right out of the package. From that point on they are on a steady decline. I typically toss them after 2-3 days. I recently bought some 801 cartos (brand unknown) and 510>801 adapter. I would say that these are every bit as good as the Boge cartos. I'm using my first today, so staying power is not known yet.
My search recently took me into an experiment with Clearos and CE2's. The Clearos were a dismal failure, although I later found out that the total failure was because of the type of juice I attempted to use in them. But hell, if a type of juice (IE: apple, cinnamon, mint, citrus) is going to have an impact on something, I see no real reason to proceed further with that unit. My departure into CE2 world was only a single CE2- First issue is they are a PITA to fill. And since they are not clear, you really have no way to tell when it is full until it starts over flowing... But then I got 2 or 3 good tasting hits, and then it went straight to that dry carto taste. I loosened the inner seal so it could wick better, but still had the same issue- 2 good hits, then nasty dry taste. Then I would have to let it sit for a bit to get flavor back into the wick again. if I wanted to go thru this much effort I would just drip. I now have 4 new CE2's that are destined to the hall of shame shelf to collect dust.
Recently discovered Jumbo KR808's and bought a package of those (along with a 510>KR8 adapter). This thing holds a lot of juice, but my first use has been less then stellar. The verdict is still out on these, but so far it is not as good as the good old Boge cartos.
And the search continues...........