Received the RTA today and tried it with the pre-mounted coils.
Compared to the standard 0.4 ohm coil, I feel a warmer vape with the RTA, most probably due to the dual coil setup.
With a "Orange cream" DIY liquid on a 2.5mg 15/85 PG/VG base, it gives the same vapour and almost identical flavors, perhaps a bit more fruit on the RTA.
I managed to fill the fatty tank with the RTA with almost 4ml (when the fatty with normal coil accepts 5ml).
(and I still have problems posting an image ... :(