It's pretty interesting what setups different vapors end up liking over other setups.
Myself, my favorite is the cartotank. Like r77r7r said, with my Slap-Yo-Momma tank tool, I can refill a tank in about a minute. Start a fresh carto and empty tank in about 5 minutes which will last me all day or more (in a 2 ml tank), and by simply refilling the tank after it gets low on juice, the carto should last me a over a week with multiple tank refills.
I found clearo's and clearo-tanks (vivi nova) to be very hit or miss. Just the quality control of the clearos out of the box was hit or miss. Some DOA, some only lasting a day or two, some lasting me 3-4 weeks. And then there were the leaking issues. I found the vivi novas to be extremely easy to use and to produce great vapor, but with some juices the flavor was extremely muted. A couple of flavors were so absent that had I not known what I put in the tank, I wouldn't have had a clue what it was.
Having said that, I know that others have had the exact opposite experience. The important thing is to give everything a try and see what works best for you.
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What is this Slap-Yo-Momma thing, you might ask? View the following PBusardo review and demo: