I also use a Nautilus and I love it. My husband uses a Aerotank as well as a Nautilus Mini -- he likes them both equally, but when he was given a choice between another Aero or the Nautilus, he went Nautilus.
For me, I couldn't be happier with my choice as a new 'vaper.' I may the odd ball out, but I appreciate the aesthetics of it, having that vintage, early 1900's apothecary vibe is inline with my style. All the pretty stuff aside, the functionality is awesome. I am using the new coils and they are incredible, but the standard kit-included coils were great as well (two different ohms). I get a great vape from both, nice and warm and very smooth. I like the airflow holes as well, and the way it locks is pretty point-and-click simple.
I've only had one crisis when I accidentally pushed the pin in on the bottom. Oops. But that's user error. Just be aware if you get it to set it down in such a way that you'll avoid pushing that pin.
The only down fall is the glass (this hasn't been my experience -- knock on wood -- but I've heard it said a enough times that it warrants a mention). It's strong, I believe it's pyrex, but regardless, it's very unprotected and you have the soft round edges where glass naturally thinner anyway. If you're tossing your set-up in your purse or pocket while on the go, you could break it. I'm getting the "cage" for added security, but if that's not for you Aspire offers several options for replacements if it breaks or if you just don't want to the run the risk -- solid stainless, the cage, plain replacement glass... All of which are super affordable.
What a fun decision to have! Let us know what you end up with and how you like it!