I've had a 2 tuner tablo that has been great. Occasionally, I would have issues getting local channel 22-1 (Hattiesburg MS, solid green reception, tower is very close). The solution was to drop it, rescan channels and add it again, sometimes a restart was needed. Since the last update, this doesn't work. Any recordings on that channel are 3 minutes and then a fail. If you watch live, you get 2-3 minutes and then it's stuck on "loading please wait". If you go back, you get a replay of the same 3 minutes and then it's stuck again.
I've found that switching to HD 720 5Mbs fixes this. No extensive testing, but I got a clean 30 minute recording. I had it set to HD 1080 8Mbs, what I would prefer.