have to agree... so far (fingers crossed) my 630 has been flawless in recording and playback.
The screen resolution issue (zoomed top left corner) when going from HD recorded to SD live is a bug to me, but apparently it is being worked on. I have yet to really put the machine through its paces, but it has handled multiple recordings, ppv recording while switched off and has scheduled shows for the week of the 20th well!
I said before, pixellated playback sounds like a harddrive issue- I would escalate.
Shaw Direct DVR830 / DVR 605/ 605, Sony Xbr65" 950E", Sony XBR4 850d, Oppo 980H, Yamaha 7.1 Surround, PS4! WDLive