I have 4 of the top 5 tanks. If you’ll bear with me, I’ll give my impressions…not so much a review just personal insights.
1 TFV4. I’ve only had this tank a couple of days and only used the pre-installed triple coil head so far. It rocks for sure. Once primed, the flavor is surprising from a sub-ohm tank. The juice capacity at 5ml is nice, but don’t expect it to be that obvious compared to others when you start using it. It drinks juice like a hobo drinks wine. The top fill feature is exceptionally enjoyable and easy
What I think may be trouble down the road -
Top fill cap. Things loosen over time and I’m wondering how well that little hinge will hold up. You’ll be swinging that door open often seeing how refills will come more frequent than most tanks. There is a lip that grabs this hinged lid which should certainly aid in reducing wear, but time will tell the story here. Additionally, to take the thing apart for cleaning or to change coils you must unscrew the top section from the bottom which is connected via the chimney to the coil. Then you must pull the glass out from the base. There is a little…very flimsy gasket in the base where the glass seats in. This came out when I first filled it. However, seeing a bit into the future I moistened the seal with juice hoping this doesn’t come out next time I change coils. We’ll see. Other than that and the fact you need to push power - 70 watts seems fairly miminum for the triple coil - this is a solid and well manufactured tank. And for something that blows the clouds, the flavor is nearly that of an RDA.
2 Crown - I don’t own one.
3 Delta II - I’m hooked. I don’t buy the manufactured coils anymore because the rebuild deck is easy to build on and the thing works like a champ with it. However, I never had a problem with the stock coils except for a box of nickel ones that I bought. They sucked but I think it was a bad batch because I’ve seen others use them with good success. This is by far my favorite sub-ohm tank due to the cloud production and flavor. In my opinion it has the TFV4 beat for flavor. The sweet spot for me is 45 watts.
Cons - it can be a pain to fill. Once you’re used to it then it’s not bad at all, but the space between the chimney and edge of the tank makes using a bottle dripper a bit cumbersome. Still that’s how I fill mine and it’s easy now. The thing is also a piece of solid construction except for where the base screws into the tank. If you ever drop and break the glass, you’re done as it’s a sealed, non-serviceable item.
4 - Kanger Subtank Mini - For what it is, it’s not a bad tank. It’s easy to use and has decent flavor. And it does have a decent tank capacity so running at 25-30 watts (35 if you put major suction on it) it seems to sip at the juice instead of guzzle it so fillups are less frequent. The organic cotton used in the stock coils is good too. Problem is it won’t wick liquid fast enough which is why 25-30 watts is about the max for normal vaping. For that reason I use the rebuild deck.
Cons- the 25-30 watt limit kills this tank for me using the stock coils. I don’t get the satisfying volume of vapor that keeps me coming back like some other tanks do. Really that’s the only complaint I have. The Subtank Mini very well manufactured and easy to use. I would call it the perfect introduction to sub-ohm vaping or for someone who wants more vape volume but still keeping a lid on it.
5 Atlantis 2 - I don’t like it. I had some very high hopes for this tank but feel that aside from a redesign of the air flow and lower-resistence coils, it’s the same as the original Atlantis where you sacrifice flavor for clouds. I bought mine a couple of months ago, filled the tank and it still has half a tank left of that first fillup. Look for this to be a giveaway soon and I don’t recommend it to anyone who wants more than blowing big clouds - which you can definitely do with the Atlantis 2.
It’s a HUGE head! 
