just got mine the other day from fasttech (reload styled RTA black 27mm does not stay stainless steel in description or whatever 11th of May 2018 if I recall)
used Smok Beast tanks (TFV8 Beast as well I own Big Baby Beast) flavor was "ok" but only if you run at high watts with just the right coil and keep upping and downing the watts to prevent cooking the liquid on them (was major pita)
numerous other tanks after I had "cracked" it trying to use the crappy RBA deck on it which came in the kit (completely killed one of my box mods from a short... stupid smok not testing parts..I really loved that previous box mod because I could LOCK the fire and the wattage and still use it, whereas this Alien 220w you cannot lock and still use)
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Aspire Nautilus (flavor really not that good TBH, coils not last very long, tank got quite hot and was very restricted MTL or ATL because of very narrow drip tip.
Kanger subtank (forget actually model, but used the ceramic coil .35 ohm in it...flavor was actually pretty decent for ~1 week then dropped very quickly)
Goblin V2 (dinky little screw hole to actually fill it (decent flavor, but quite a pain to constantly deal with when filling it)
Got Troll RTA (v1) flavor once got used to it was pretty nice, but, getting the wicks just right and the coils in just the right place to get the most of the flavor/airflow and either not getting dry hit or leak was/is a major pain, though the refilling or being able to take the bottom of tank off, when liquid was in it was a very nice thing (compared to almost every other tank on market) used for ~5-7 months (using for awhile)
Got OBS Engine ~2.5 weeks ago (fasttech) the coils that it ships with are "ok" but they almost get too hot when you fire them where they like to be fired and almost cooks the flavor right out of it, likely the size of tank, or the vapor tunnel was not large enough for what these coils want to run at.
I rebuilt with 8 wrap 26g Kanthal A1 3mm ID Rayon wick (read as .645 ohm) the 100% rayon sally beauty supply one..had to rewick a few times to "learn" it) flavor is actually very nice now (quite close to troll RTA but ZERO leaking can happen in comparison)
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Got this Reload Styled RTA 27mm last week (same but 7 wrap 3mm ID Rayon single wire Kanthal (like did with OBS Engine minus 1 wrap) reads at .545 (auto-set wattage mode HIGH Alien 220w..effectively 1 less wrap reading ~.015-.028 better than it would be at minimum in many many coil builds over many many tanks says the design has very good contact with positive/negative)
I screwed around trying to get just the right amount of wick and nestled up and close to airflow (like so many online reviews say you should be doing) and while flavor was "ok" almost always felt like I was sucking thick milkshake through a straw,
rebuilt, rebuilt, rebuilt....lost the 510 pin until I found it on the floor later evening on the 20th (in use maybe 2.5 days TOPS) rebuilt it once again, still felt like milkshake through a straw suction....grrr....so I flipped it on the cap (once again leak like crazy) moved the coils away from airflow ~1mm.
sure as heck airflow is AMAZING now (far far better than any tank I have even used, except maybe OBS Engine or Beast tanks full open, properly wicked/high flow coil) but even if not able to do mach 1 airflow (who needs this when get a lung full 1/3 open 4-5 seconds 50-62w flat) the flavor is out of this world. way way superior to any tank I have ever used (including a few drippers) ZERO spitback, likely fairly close to many drippers for the sheer clouds I can push out and absolutely perfect flavor, i.e vape a nice chocolate flavor that is ALL you can taste (unlike other tanks where it can be muted or cannot taste some of the small % you have added to the mix) O.O
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I had issue with airflow ring being much looser than I would expect it to be (does not fall off, but has zero tension holding it where I want it to be...have changed o ring and no longer a problem) but, for something that cost like $16 SHIPPED to Canada, I wish I would have saved the money in buying that OBS Engine, Troll RTA, Big Baby Beast etc (win some lose some)
least I got the hex screwdriver (instead of allen key like this ships with) and a couple of solid screws should the ones in this fail, got rayon wick and 26g wire to make probably another 300+ coil changes (at a fraction of the price it would cost to continuously buy premade coils from Smok, Aspire, Kanger etc)
For the 510 positive pin, I highly advise anyone looking to buy this amazing tank (suggest the 27mm "bubble" version for the extra juice capacity) make 100000% sure the 510 pin is tightened down (is reverse threaded at least it is on mine) so you do not lose it (like I almost did)
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only other "issue" I noticed is CANNOT take off bottom when juice is in it (even when it does not go over the "tunnel" or it will absolutely leak out of the top .unlike TROLL RTA where I could keep ~80% full tank and as long did not have the juice over the central "tunnel" it would not just dump the entire tank out of (I think is the drip tip)
I think for the top cap is, no o ring that I can see, though the included glass drip tip has a tiny one on it, it may not fully seal to the "tunnel" so the mm gap or so gives an automatic place for juice to go right out the top of it if flipped "upside down"
I cannot see a way to make sure top is leak proof like the TROLL RTA is (which I love about it) but still is a solid tank (especially for 1/4 to 1/10th the price of comparable flavor/cloud chucking tank I have personally seen or have used) flavor really is out of this world, nice thick juicy clouds even compared to TROLL RTA (close to many drippers, not quite there, but close) which I found was best I used prior to this (minus the potential wick/coil not done right factor, Troll RTA done PERFECTLY vs this, this one no contest)
I have used some drippers in the past, I would put this against any other tank (at the wattage I am running/build am using) and likely this little tank will win hands down.
I think IMO they need to figure out a way to make sure you can ratchet the bottom down nice and snug so less of a chance when you make sure it is not "loose" on mod that when you try to take the tank off it "spins" the glass causing it to loosen (which sucks when dump juice everywhere just trying to make sure tank does not wiggle back and forth)
ABSOLUTELY phenomenal. likely "best $16 purchase I have made in my life. vaping may not be the "healthiest thing" but when it tastes like this who the hell cares ^.^