There is no HD channel/content from Airtel right now. So HD STB is just another SD STB until they add a HD channel/content.
This is ridiculous! Airtel rushed in to join the HD bandwagon with a "Me Too" attitude, without getting agreements in place with broadcasters to provide HD content. Atleast the other service providers had Discovery and Nat Geo HD before the start of the World Cup. As of today (July 13), Airtel has no HD channel. It's a shame that they are advertising the Airtel Digital HD service when they do not have HD content to offer.
I wonder what the big bosses at Airtel are doing! Their Customer Care folks as usual have no idea at all.