OK, first thoughts (I've been using the AFS for about 6 hours). I am using it on the Trans in the 3.7v Giant configuration (with an 18650) with 18mg generic Dekang RY4. I thought it would make a big different to the size and weight but to be honest, I am not actually noticing it being there - which is kinda unexpected but I am happy about it.....
Takes about 3ml to fill up fully of which about 1.5ml is realistically actually usable in normal operation before topping up due to the level of the lasered AFS hole in the atty. Some users will find this is more than enough for a whole day - I vape SO much that I will need to refill once or twice again during a long day.
There is a slight learning-curve on this item just to ensure the best operation of liquid flow for the particular way you vape. I found it took me an hour or so of constant vaping to get used to the best draw strength for the optimum liquid flow for me. This will all depend on length and depth of draw that each user takes, as well as liquid viscosity (I should imagine).
Follow Imeo's instructions carefully, particularly the bits about priming the atty at the beginning and about knowing where the holes are so you can hold your GG the right way up as the juice level decreases in the AFS resevoir.
The liquid does definitely have a fuller taste to it - I've been trying to work out why this is and I think it's to do with the fact that the reserve liquid gets warmed up slightly by being stored around the atty - I am imagining this might be bringing the flavour out more than when you usually drip cool liquid onto an already hot atty. I could be completely wrong about this though.
I am assuming this flavour enhancement factor is going to be very useful for those who either like a much stronger taste or who want to cut their liquid without losing much flavour.. I notice a better throat hit also, which is unusual for me - hardly anything gives me a throat hit any more.
So, those are my impressions after roughly 6 hours use.
Don't want to go back to dripping after this!!!