Got on both me 501 and 510. It's nice but slow (as are all the interactive apps). The radar (for San Francisco) is a bit sad. It's basically the whole western US, plus it's too small to boot! Its kind of useless. You'd think they would expand it to the entire screen. The Close button for the radar is in a goofy place also (off to the rigth of the radar window like a wart). Something else annoying is that using remote the cancel button just takes you to yet another dialog that ask you "you really want to exit? Yes, No, or Cancel". Cancel is the default, so you have move the selection to Yes and push Select. Great, more useless key presses. Unlike every (almost every) other Dish window where Cancel is the same as Exit.
I'll might use it, but they could do a much better design.