knuck3ls

99% of any DNA200 issues I've seen so far have been mod maker issues and mostly the mass produced ones at that. I have 3 DNA200 mods from small facebook type-ish mod makers and no issues what so ever.

Power mode doesn't use any type of pre-heat function. Not sure what differences you were experiencing honestly, it should be exactly the same.

I've read the VTbox200 is pretty terrible, but the Hcigar VT200 is leaps and bounds better. Pretty crappy they both use the same VT200 name.