I have used Dish Tv for 18 months and shifted to Tata Sky around 2 months ago.Here is a comparison based on my experience:
Installation:
Dish Tv: Went to a dealer, made the paymnet in cash. H/w was delivered after 2 days. Connection not activated. Cust care said payment not received from dealer. Dealer said payment already made. Had to fax the receipt to Dish Tv. Connection activated after 1 week.
Tata Sky: Called cust care. Payment made by credit card on IVRS. H/w delivered in 2 days. Installation done next day. Connction activated instantly.
Customer care:
Dish Tv: Service Extremely poor. Takes a long time to get connected to a cust rep. Staff not well trained in solving problems. No response for complaints lodged online/mail. For servicing issues, all matters are redirected to the dealer. The website is difficult to navigate. Billing is confusing.
Tata Sky: Have to dial a STD no.from a non BSNL phone but get connected to a rep immediately. Staff well trained and polite. No hardware issues yet. User friendly web site. Simple billing.
Channels & Cost:
Dish TV: More channels. Works out cheaper
Tata Sky: Less Channels. A liitle costly.
Picture/Sound quality:
Comaparable in both.
Ease of use:
DishTV: A little cumbersome. Channel changing is also not quite user friendly.
Tata Sky: User friendly controls.
Overall experience:
DishTV: Bad. Would not recommend.
Tata Sky: Good experience so far. Recommended.