It's a little early to know about the VTC's battery life, but the D2's seems acceptable.
The charging though... I believe the D2's barrel plug and charge board are a higher amp than most.
I think the norm has been 0.5A moving to 1.0A lately, and the D2's is almost certainly at least 1.0A.
It's quick alright.
Battery life IMO is more about what you put on it and take out of it, hard to compare that between users. Then if they change between mods like I do it's real easy to get a wrong impression.
So it probably wasn't an outlet issue. I kept looking over at that thinking it was taking forever.
But then again the VTC is easy to swap batteries on and I can't imagine there being a potential problem with it like there is with the D2.