I'm still playing with mine, but I'll share impressions so far...
I, too, am coming from a NO2. Last night, I put the exact same amount of herb in the stem of the E-Nano as I would put in the NO2. Poor, poor tiny little pile of herb..
I am using the glass screen stem, and yesterday, after cleaning it, I added one of the little screens from the other stem. My herb was a very thin layer in there. I have the E-Nano at about 7.5 on the dial.
I don't slide the stem all the way onto the heat port, as when I did that, it got kinda stuck. I just pretty much hold it just over the tip of it, and inhale really slow. Wow, btw. Deep vapor... as in I breathe out, and whoosh, there is more vapor at the end of my exhale!
I got at least twice as many tokes [new terminology for me, hope it's correct] off that pathetic pile of herb than I would have out of the NO2. I love that, after I toke, I slip the little cap (off the test tube it came in) over the open end of the stem, and set it down. My herb is not continuing to cook! It's just waiting there for the next time.
When herb got spilled into the Nano... well, gosh, it just falls right out when you turn it over. No mess. And I've soaked the stem clean once, and that was SO EASY!! All those little parts of the NO2...
It is a little bit harsh on my throat, even with really gentle, slow pulls. I'm still hoping to eventually pair it with a water tool. However, I think that I can get used to it if I'm careful. Keep in mind, I have no history of any of this, so my body is still adapting.
All in all, I love the Nano.