Well having sampled dozens of flavors from not only one vendor I know the feeling about trying to keep track of which flavor is in what tank! Some are custom mixes I made up for taste testing a menthol with another to see if menthol and the other will work together. In one 120ml bottle I have several "remnants" of samples I would get in one time only when ordering hardwares.
A good number of people seem to like the KayFun tanks while I wasn't in any rush to abandon the Tumblers entirely either while those are run on the eGo-V VW type batteries. But I now only use so many compared to the number of those I collected before the sub ohms were even heard of. I didn't abandon the Nautilius tanks any keeping one on each of the 20w iSticks as well as the Vamos, MVP 2.0, and MVP 20w while the 15w max VTR sees the pair of Eleaf Melo sub ohm tanks put to use with that when I have some new flavor to try out on different set ups.
As for the sub ohm tanks being better that will depend on who makes it as well as what ejuice goes in. You won't always suddenly see a tremendous boost in vapor output or more robust flavor. A lot depends on the particular ejuice and how well that wicks up even with the better coils! Originally when CCV was first starting and I was doing the initial sampling with the old CE2 stuff the first several flavors put very little vapor out at the then best flavor ratio of 70PG/30VG since 50/50 was "wimpy" and 30/70, 20/80 was "what's this stuff?". Then came one flavor that made the old tanks go to work!
Now before assuming anything I went back to those same old flavors with each newer type tank and when the sub ohms arrived those early flavors do put out vapor! Maybe not as much cloud making capable but see more potential as the newer tanks have improvements seen in coil design to be more efficient. So it's not only watts and resistance but quality you look for when trying to find the happy place you want to be at regardless of the set up. The Tumblers. Nautilus. Melo while nowhere as good as the other sub ohms including the iSub Innokin's much needed improvement compared to the IClear series, and other older tanks like the Viva Nova still have application.
Before I forget and while we are on the subject about sub ohm tanks I recalled an article that fits this matter quite well as far as Is a Sub-Ohm Tank Right For You?
The first thing I heard out of one person who was a regular Nautilus user as well when first trying out the Atlantis was: "I'm not going back to the Nautlius. The Atlantis... " blah blah blah Atlantis praise! was heard. The findings here having one been a somewhat heavy 3 pack a day person was that the sub ohm tanks with the performances they offer would seem more suitable for the previously medium to heavy smokers as far as getting more satisfaction not only from more vapor output but also seeing a more intense flavor experience in respect to getting more flavor of those ejuices which lack otherwise.
No one can tell you what you will find to be that happy place I was just referring to in both hardwares and ejuice. You have to find out what works for "you"! plain and simple.