I have been using Tata Sky at my home for the past 6 months. So far we are not having any issues with respect to clarity of picture or channel availability. Tata Sky do have a couple of good packages for their annual subscription like South value pack. I found this package to really good for a annual subscription of 2000 rs. It has a good mix of the regional channels we watch and also the major hindi channels like Setmax, Starplus etc..News channels are also available for this pack.
Some of the things I would like to point out to anyone who is trying to buy a Tata Sky DTH is that the installation time will depend on how good ur vendor is. We had a really harrowing time chasing them to install the service. We called the tata customer care multiple times. Thanks to them finally our issue was sorted out. Second is the add on packages. Most of the add on packages are sports channels or kids channels. So you cannot get a particular regional channel or hindi channel as add on package.
Apart from that there are no major issues with respect to payment if you can pay online. I like their movie on demand feature and most of the recent bollywood movies are available at Rs 75/ within a month of their release.
I feel in these days of multiplex it is really good thing to watch the movie for Rs 75 with the entire family