I have the essentially same Tosh DST-3000 (mfd by Hughes), no problems yet in 7 months of use.
Did a lot of research here and at Home Theater Spot and the Hughes made boxes seem to be the most trouble free units around.
It can receive standard and HD from both satellite and ota. It will upconvert everything to 1080i and send it out via component, or downconvert HD to 480i and send it along with native 480i stuff via S-video, which is the best way to watch native 480i.
It will not output ABC's 720p, but converts it to 1080i. The resulting picture looks like native 1080i from HBOHD or Showtime HD.
They do get pretty warm so need lots of ventilation.