So I have or have had 5 sub ohm tanks. The TFV4 is by far the best. Best flavor, best vapor, best design, best everything. I love that tank.
Ranked by my preference:
1. TFV4 - I have 3 of these, they are amazing.
2. Billow V2 - Beautiful tank, fantastic flavor, I just wish it had more air flow.
3. Aspire Atlantis V2 - Pretty standard sub ohm tank. Good air flow, easy design
4. Horizon Tech Arctic - Again, pretty standard sub ohm tank. Comparable to the Atlantis V2 in most ways, except the juice well goes well below the glass, and you have to tilt it on its side to see if you have any liquid left.
5. Kanger Subtank Mini - Did not like this tank at all. To date, it's the only tank I've ever given away.
I think the RTAs are great on the go. As long as I wick my RTA properly, the sub tank mini never leaks.
I will have to try a TFv4. I like the sub tank, but I feel like there's gotta be something better. TFV4 doesn't come with the RTA? That kind of bugs me, but oh well.
the TFV4 is the tank of options. There are two (four) versions. The Kit and the Single. The Kit, among other things, does come with one of the RBAs. The Single does not.
The MSRP on the TFV4 is $50 for the Kit and $40 for the Single, but since you'll spend $10 on an RBA anyway, it makes sense to get the Kit.
All that said, ecig.com does have the Single for $23, which is an absolute steal. http://www.ecig.com/smok-tfv4-tank-single-kit.html
Good stuff. Will have to do some shopping after work
Edit: Will have to try both the TFR1 and 2. Do you have any preference?
Looks like the full kit comes with the Clapton RBA. I would assume it would work with normal coils, but I might get the TFR1 too just to be safe.