I have been using tata sky for about 8 months now. I had taken the initiative of installing tata sky in all the houses in our residential area.
There is no doubt whatsoever, about the clarity of the picture. The picture, as they rightly advertise, is of DVD quality. The customer service is also great, except that you may have to wait in the telephone queue for sometime to get through to the executive.
But there are some areas where the service is found to be inadequate.
Rain Rain go away: This is one of the problems that we face in our locality. The moment rain starts, the programs go for a toss. We get a message informing us that the set top box is unavailable to receive the signal. I talked to the customer care, and also to the local engineers, who admit that there is a problem during heavy rains. But my experience is that this happens even during light drizzles.
Bouquet of channels: Tata Sky offers lot of options when it comes to channels. They also offer the full bouquet of channels at Rs300 per month. Even then, it has been noticed that some group of channels - like the Sun network(popular in South India), Neo sports(from Nov1 onwards), and some channels of Zee group are not included in this bouquet. To view some of these channels, you have to pay extra.
Recharging: Another area of concern is the recharging activity. As you are aware, the subscription has to be recharged just like the pre paid cell connections. More often, the authorized shops selling these vouchers run out off stock. Though there are options like recharging online, and also through mobiles, there are people who would be happy recharging through coupons.