Horrible experience. With TV & 721 off yesterday evening, I noticed the green power light flashing. Turned on TV, saw black screen with red swoosh and "testing...". Went back later, no output from 721. Held down power button to recycle, no response. Left it alone. Later unplugged and replugged it. No output at all from 721, just some spin up noise. Figured I'd lost 721 #6 and went to bed, planning to spend part of today on the phone with Dish. This morning, working fine.
Glad it was just an ill timed update. I hope to get at least a couple more years out of this 721.