people said:
maintain the airtel for sd and buy d2h minimum hd plan,you can enjoy both sd and hd.just one time investment,but i thing software didnot improve the channel quality if depends on hardware.
airtel SD is at my native. in chennai i have only SCV till now. but not satisfied with my new HD ready LED TV. so planning to move out of SCV and also to move to HD. I think D2H is the best choice since we have more number of HD channels and maximum tamil channels.