Iown use and love both the Nautilus and the Silo even more, I have ordered an iStick but do not yet have one. While I would be happy to share my thoughts, I am just a guy that vapes rather than smokes, it is not really a 'hobby' for me, nor am I a collector just to have a thing. I do not rebuild because I have lousy hands, and am not capable. So I look at total cost of vaping (fixed income). I used to be a carto/tank guy, but so far the heads last longer so total cost between the two makes using the Silo cheaper for me than carto/tanks did. Plus, I actually discern a minor increase in flavor in this swap as well.
The reason for liking the greater airflow choices the Silo offers is for me, heads start to draw harder with age, and usually I must swap heads when it seems like I am sucking fudge through a straw. With the Silo, I can simply open the airflow more and get roughly another week out of the head.
Any such review coming from me is non-technical, as I have no tools for measuring anything - making such a review simply an opinion.