Think again, all of you. I have a 722 purchased pre "K". I also lease two 612's which were apparently new (not refurbished). One of them has given me no trouble whatsoever. The other couldn't scan in any OTA channels until I added a trap for WNVC which is about 2.5mi away from me and wiping out it's tuner with a very powerful signal. (This happened to other ATSC tuners I had as well.) Every once in awhile (maybe once/quarter) it looses it's connection to its disk and needs to be unplugged for a few seconds. This could be due to crufty power, as I do not have any UPS on these boxes.
My 722? Don't get me started! It has several times gone berserk and deleted all my recordings, or as many as it could before crashing. It's latest quirk is to go blank on TV2 and refuse to turn on. Hard reset needed to clear that condition. It has quite freqently gone blank on the video on all channels. We can see the banner when changing channels, and we can look at the guide, but we see no video and hear no audio. Search on disk overheating problems, if you want to get your eyes opened about the 722.
All in all, I think a lot of 612's went out with bad disks. Other than that (and in my particular case), the problems with the 612's are minimal and less serious than the problems I've had with my 722. If you get a 612 with a good disk, you'll be pleased. (No PIP though.)
I hope this is true about the 612s, but we got two bad ones. hopefully the replacements will not have the same issues. Could someone start a poll about the 612 since there are a lot of people thinking about switching to them to see how many people have had problems and how many have been fine. I think that would be very useful, I don't know how to do it but hopefully someone else could set that up.