In my opinion Tata Sky is the best DTH service provider. Picture quality is great SD as well as HD. I am a subscriber of this platform for the last 10 years. Being a technically sounded guy, as much as I can say that Tata Sky never disappointed me even for a single time till date within a very long time span of 10 years.
Those who do not like the picture quality of Tata Sky, there is a mess in their TV/ Tata Sky settings.
If you do not understand anything, then talk to the customer care of Tata Sky, they will solve your problem.
I also want to clarify that I am only a consumer/subscriber of Tata Sky.