We had the 612s for about 3 and a half months and one of our 211 with EHD for almost as long. The 211 is much more reliable, and if you don't really need two sat tuners you will be much happier with it. Like I said in my post the CSR found out he could not send us another 722k after we had the first installed, so we actually opted for a 222k as a replacement for the second 612 and turned the other 211 we have into a dvr to replace the 612, we just wanted to get rid of them. Plus, you will have much more space with an EHD, the only problem is the limitation in timers, its about 20, but since it sounds like its for a secondary tv it probably will not be an issue. Plus if you have OTA it will have two tuners to record on.
Been almost a week now and everything is working well, would have preferred two 722ks, but I think the compromise of getting an owned 222k and buying another EHD for the second 211k is much better than keeping the 612 with all the problems we had with them. We still get some rare hdmi dropouts with the 722 which the 612 also had, but if you skip back it plays back fine, that was the big problem with the 612, 90% of the time it was not the hdmi problem, if you went back the same thing would happen and you would lose parts of the program because of it, sometimes lasted 5-10secs.