I personally seen the two, side by side, and no offence I won't go call Videocon's DTH service as HD (it just looked like a cropped SD to my eyes, bloody articrafts everywhere). ADTV is WAY better than VD2H IMHO, thus I went for it, and for past nine months I am happy, very happy with the picture quality, and to be honest with price too, when compared with Tata Sky and all. I find the packaging of TS just stupendous! And ADTV's UI is decent too, TS is better, but I can't complaint anything about ADTV other than the stupid and rapid BAT updates pop up especially in the middle of the screen and in middle of a game. I can't speak for the sound, as I do not watch any shows / movies on it at all, but on some HD channels I have seen it's mentioned as DD, but not always.
And their CC just sucks. Just some idiots sitting there, average IQ of around 60 max. But I found the service via Twitter very fast. In past nine months, I needed to contact them once (and that's too just because my recharge wasn't processed, not anything hardware wise) and I believe that CC won't be needed in long run, other than in case of a natural calamity like a big storm or something.
So in short, if money matters (for me it doesn't, but it matters when for same PQ and less channels I pay more, a lot more, which is the case with Tata Sky, that's just dumb to me) and you need a good PQ DTH serive, ADTV. If you are not interested about paying whatever been asked, Tata Sky. If you need to use every cent of your hard earned money, Videocon. But again, I emphasize the HD PQ is NOWHERE near as of TS or ADTV. I don't care what that Dino guy tries to advertise about Videocon and childishly claim it's PQ is better than TS / ADTV, I have seen both of them personally and eyes don't lie and that guy is an idiot and rightfully banned from literally all the DTH forums.
PS : Forgot to mention about one more important thing, if that concerns you of course, the disk size of TS and ADTV is bigger than D2H's, and the connection restores back within 15 minutes in case of sudden lightning and rain for them, but with D2H it's just crap. Connection stability should be given a thought, as DTHs (almost all of them) un-stability in poor weather is the biggest gripe of them.