I'm exclusively using Nanos - one is Used (from here), one was new (gold, from china) - both purchased this last winter. I even got a buddy to leap upon one here that was lightly used.
Love the simplicity, flavor, lack-of-leaks. The only niggles are:
- I wish I could tear it down further for cleaning;
- I wish we could find bubble-glass replacements
- Some sort of coil-height gauge for the hidden airflow
#3 is not horrible: you can diddle around with depth-gauges/calipers and get close - your answer is also useful.
Only bits missing from your Retro-Review would be, (particularly since this is RETRO):
- Where can you get replacement glass? (what size)
- Replacement seals?
- Comparison against some of the top Single-coils: Serpent Elevate, Kaees Solomon 2, etc (I'd have perhaps checked against some of the top-scoring tanks that @Vaping With Vic and other UK vapers have covered)
I've yet to see anything today that is Superior across the board.