A little update on those Modenas.
I was getting worried last night because when I gave them a try the LED lit up, the liquid gurgled, the atomiser hissed and crackled, and virtually no vapour was produced at all. This was the same for all the atomisers and batteries I received so I figured the problem was with me. On the plus side, I did discover that none of the batteries or atomisers are obviously broken.
I put a battery on charge overnight and using that I'm getting some vapour, although not as much as with my Pilot and nowhere near as much as my Dura. I'm thinking that the atomisers need to be broken in before they start to work properly, but I can see why they'd cause big problems with returns.
No problems with leaks yet, but it's all too easy to get a taste of liquid through the mouthpiece while frantically trying to suck hard enough to kick the atomiser into action. Oh yeah, the batteries have the Dura-style 2 second cutoff (easily worked around by varying the suction when you take a drag).
Update. Vaping away while I was writing this and the first atomiser is definitely improving

It's almost up to Pilot levels now, albeit with a *very* light draw compared to the Pilot's "sucking through a blocked cocktail straw" feel or the Dura's perfect balance.
On the whole I'm pretty happy I got in on this deal.