OK, here are my measurements:
1. Cart duration: The cart lasts about 315 puffs that is easily a pack, slightly more. I used to take 2-3 sec inhalations into my mouth, on a Leaford 5 sec scale it would be obviously less. But, what is more important and obejective: the cart holds 0.74 g liquid (to compare: DSE-901 carts hold 0.42 g, M-410 holds just 0.26 g). By holding I mean refill capacity, so a completely empty and dry cart would hold more, but you don't usually refill completely dry carts anyway.
In my opinion, that's fairly acceptable.
One more thing about refilling: I've found a better way to fully refill the cart: remove white cap, remove silicone ring. Insert the silicone cork into the hole (thread side) and top up fully the cart (don't bother the inner hole). Let the liquid soak into the sponge for about half an hour, then pull out the cork, mop up any excess liquid from the battery side of the cart - and now you have a fully refilled cartridge.
I have refilled one cart 4 times so far with this technique, and it still works like a charm. I wonder if these "disposable" atomizers will last longer than the ordinary ones, which would be a shame.
2. Battery duration: The batteries last 300 puffs (with the above mentioned inhaling technique), that is pretty impressive (although just half as the advertised). No wonder, the battery is rather thick and long (longer than the DSE-910).
To sum up: so far, so good. The only weak point could be the switch in the battery, but for now that is just a speculation.
Oh, one more thing: the throat hit has improved a lot with my old favorite RS mint, but still not that stunning as I hoped.