I personally still don't like the fact that "tank" is sometimes used as a catch all term. There really is no right or wrong, all these names are made up anyway, but it seems to me tank should refer to cartotanks only.
The first tanks, as far as I know or can remember, were cartomizer based. They were home made custom pieces made, generally, out of syringe tubing. After tanks started getting made by manufacturers, some began to use the coil/wick setup instead of a regular coil/filler setup. You can obviously get CE2 style cartos and use them in a carto-tank, but if you consider the interface between the juice holding and juice vaporizing components, it's still a carto-tank, it uses cartos to function.
A vivi-nova or clearo doesn't use a carto, it uses a coil/wick head on a post. To me that seems like a very easy and logical distinction between the two terms. If it uses coil heads, it's a clearo. If it uses cartomizers, it's a tank. Vivi nova falls into clearos seeing as, functionally, it's basically identical to a clearo. The shape, materials, or size of the clearo doesn't stop it from being a clearo. It stops being a clearo, and becomes a tank when it uses replaceable cartos to vape juice, not coil heads.
Obviously this is just my opinion, and I am constantly harping on about this kind of thing because I think it's ridiculous when there are terms that mean 3 different things. We as a community should decide specifically what terms mean what. It's far less confusing for new people when they don't have to try and figure out what is being discussed.
Back on topic:
Any vaper that is actively trying new juices and frequently switching flavors should have at least one dripping atty sitting around. Doesn't have to be anything special, a generic $5 one will work. This will allow far easier flavor tasting than even clearos. When trying a new flavor you can just drip on top of the old flavor, and a few vapes later the old flavor is generally gone. Or you can blow out the atty, dry burn it, and rip. Or wash it in water, but then your kind of getting into clearo difficulty of changing flavors.
As much as I love cartotanks, I will never put a new juice in one. Tanks are reserved for all the big-boy juices that make it past the testing phase. Even though I have more tanks than cartos (and I've got boxes of cartos) it just isn't worth it to vape a bunch of juice you really aren't crazy about.
You could always take the juice back out, but I try to give away juice I don't like, and figure some people don't want a bottle of juice if some of it had been sitting in a cartotank for a few days, all the transferring of juice seems to increase the chance of some sort of contamination. Maybe I'm just paranoid because of my brewing knowledge.