If your 1TB WD My DVR Expander didn't give you any trouble and you're not planning on reusing or repurposing it I'd pull it out of its enclosure and give it a try first. (That will void the one-year warranty of course.) I'd run WD's Lifeguard extended diagnostic on it to be sure everything's okay. There's no reason to think that it will be any more or less reliable than any of the other drives you could buy. The 1TB WD's in our TiVo's have been flawless. I'm also using some of the 1TB Hitachi's mentioned and a 500GB Seagate DB35. All run cool and quiet. If money is no object I'd probably opt for Western Digital's A/V dedicated WD10EVDS (would need the "Intellipark" feature disabled per the first post) or the Hitachi which has quickly become one of my favorites (adjusting the AAM will make it very quiet). Fry's has the retail kit in Renton for $89.99 if you can't wait.