I have been running my subtank on my mechmod for two days now, and it works like a charm!  
As my vaporshark rDNA has a faulty button that works when it wants to, i had to send it back to the vendor. So meanwhile im only using my mechmod.  
I were running only RDA's until i tought about the 0,5 ohm coils and that it would turn out to under 40w, so i gave it a go.. must say i am very impressed! 
  
Mech mods are also my preferred mods, as they just work every time you press that button.