I don't agree with you.
Most transmissions are in 1080i, so outputting it to 720 p means transcoding twice (1080i -->720p by the STB and 720p --> 1080p by the TV). This can never give a better result.
Better use either 1080i and leave the deinterlacing to the TV or 1080p and leave deinterlacing to the STB. No transoding (on most HD services, and if it's a 720p service only transcoding once that needs to be done anyway)