I have both tanks, and quite honestly like both tanks quite a bit. I don't think either of the tanks would be a mistake and both give a very enjoyable vape. But there are slight differences in the tanks that may affect some buyers decisions.
Just to be very clear, I like both tanks and don't regret either purchase. I vape both every day, and will continue to do so. The addition of air flow control really takes the vaping experience to the next level, and I think this would apply to just about any topper out there. In fact, I even prefer RDA's with air flow control. Why? Because I don't vape the same all day long. I like to have a nice flavorful mouth hit to experience full juice flavor with less airflow much of the time, and then open up the air to to get enough vapor to chew on at other times. Variety is good in most things.
So having said all of the above here is what I think of both tanks in different areas I think are significant to my vaping enjoyment.
Ease of use:
Both tanks are dead easy to use out of the box. No real difference between them. Just fill from the bottom, screw them on the mod and vape. I know a very few have had trouble out of the box with each, but I believe that number to be very low with each tank and absent confirmable flaws in production or design I don't see a difference. Dead easy to setup and use for both.
Tank size and looks:
The Nautilus holds more and the Aerotank holds less e-liquid. Personal preference will dictate if this is a criteria in the buying choice for each individulal. If you vape a lot during the day the Nautilus may get the nod. If you don't vape more than 3ml during the day you may like the smaller tank size of the Aerotank better. To me? Doesn't matter one way of the other, I always have some juice with me, don't mind the tank size either way, and like the way both tanks look on my mod. I like the looks of both tanks. I think the Nautilus is a bit more stylish and the Aerotank a bit more industrial.
Flavor and Vapor Production
Flavor is very good on both tanks, and extremely good for clearos in general. It doesn't equal a RDA, but is very close to my carto tanks which is a decided improvement over other clearos I have. The Nautilus has better vapor production for me, but only by a small amount for every setting except the largest airflow. The Nautilus has considerable more vapor there. Since I vape more at reduced airflow settings most of the time it's not factor that would dissuade me from purchasing the Aerotank. But when I want a big lung hit at the widest airflow setting I do fine the Nautilus a little more satisfying. So Nautilus gets a slight edge for me here, but I wouldn't base my buying decision solely on this since the Aerotank outperforms any of my other clearos in a big way also. So I'll call them even in flavor and vapor since 90% of my vaping is not done at the largest airflow setting.
Durability:
I don't think there is a question here. The Nautilus looks great and I haven't dropped or damaged the tank, but I have to believe the covered top portion of the Aerotank will allow it to take more abuse than the Nautilus. If you're clumsy or work in a more hazardous environment like construction work, I can see this could be a decision factor. So the edge goes to Aerotank for durability. Note: I know there are 3rd party metal tank tops for the Nautilus, but I am reviewing as received tanks, not add-ons.
Air Flow Control:
Both of these tanks have brought a much better vaping experience to clearos as a result of AFC. Dramatically better in my opinion. But I think the Nautilus did it better. While I find the smallest hole on the Nautilus useless for me, being too small for my vaping preference, it might be useful for some. The other 3 holes are calibrated to an extremely useful level for me though. I typically use the second to largest hole most of the time and the largest hole when I want a satisfying lung inhale with very good vapor production. It is also very consistent because of the detents that locate and hold the AFC ring in place. Very easy and very consistent.
The Aerotank is a bit different though, while the AFC works and is adjustable, I find the AFC ring only adjusts the air in a very small range of it's total adjustment. At least 60% of the adjustment I can make to the ring doesn't alter the air flow at all. Only the last bit of screwing adjustment actually adjusts how much air is allowed past the ring. I also feel that the wide open adjustment doesn't get enough air for the same type of lung inhales I get with the Nautilus. I would like more air at full open for an easier draw and hopefully better vapor production. I don't get as much vapor from the Aerotank as I do with the Nautilus, although the vapor it does produce is still satisfying at all adjustments besides wide open. I really wish the Aerotank had not placed all three holes in the same plane. I would have rather seen them place the holes at different height in the ring with different size holes (biggest being at the bottom) so I could get a more open draw at full open and more adjustability over the entire AFC ring travel. To me this is a design flaw that could be addressed easily and bring the AFC on par with the Nautilus. And while I do think the AFC ring is a bit looser than might be ideal, I don't see this as a big issue. Another change I would like to see though is at least vertical scribe lines around the ring and tank bottom so I can adjust back to a known airflow position if I inadvertently move the AFC ring I can set it easily back to my preferred setting.
So I see this as the biggest difference between the tanks (for me) and rate this feature as an advantage to the Nautilus. Although as said earlier, the AFC on the Aerotank works well (with a few minor niggles) and I won't hesitate to recommend this tank as a result. The AFC on both these tanks truly change the dynamics of vaping on clearos in a very significant way. If all other factors like durability, appearance, etc. were the same this could sway me to the Nautilus tank. But If I were a construction worker other considerations might be more important.
Serviceability:
No real difference here. They both tear down to their component parts easily for cleaning and head changing. Both are easy to fill. And both have shown durable components after many disassembles. No issues with either. I think the construction and serviceability are great on both. No advantage either way.
Rebuildability:
Both heads are rebuildable, and in my opinion are about the same amount of effort. I have rebuilt quite a few heads for both with single microcoils and am satisfied with the result on both. It took more than a couple of attempts to get the rebuilds happy in both heads, but the results are reliable and repeatable. Each tank has it's own rebuilding challenges, but once a process is found I don't find either very difficult. Either head takes me about 15 minutes now. No advantage either way.
Cost of Ownership
Right now heads for the Aerotank are about 30% less expensive than the Nautilus heads. I have seen quite a few posts that the Nautilus heads last longer and are actually a better deal. But honestly I can't say that's the case. There are so many variables in head longevity that it would be impossible to say the head duration is due to design or manufacturing process, so since I get roughly the same duration of good performance out of both using the same juices I consider them equivalent. I haven't run across anything else that would affect ownership cost in either tank, so I think the heads are the only consideration. Since the Aerotank heads are less expensive I give the Aerotank the advantage here.
So that's it for my impressions. Take it, leave it, yell, scream, or whatever. I find both these tanks to be significant advancements in vaping pleasure and depending on what is important to each buyer, each buyer can decide the best choice for their needs. I just can't imagine being disappointed with either one. Sometimes there are big leaps in performance, and I think both these tanks have made the jump.
