Quick update... The UPS guy dropped off my WD20EARX and I got started upgrading my TiVo Premiere XL (which is 100% full). The original drive already has the 20.2 software on it. On the label it says the drive was manufactured on June 26, 2011. The wdidle3 command reported a default idle setting of 8 seconds, which I reset to 300 seconds. These new EARX drives do not support AAM according to HDDScan 3.3. Even so, I tried the IBM/Hitachi tool and was unable to change its acoustic management setting. I'm using SATA connectors to copy the original 1TB Premiere XL drive over to the new drive. The copy process has been running for 7 hours and is just under half finished. Looks like it'll take roughly 14.5 total hours. Hopefully the drive won't be too loud when I put it into the TiVo. It sucks that AAM is no longer supported, that seems like a retrograde step on WD's part. EDIT: RESULTS / FOLLOW-UP: Ok the copy finished this morning while I was sleeping. After a quick expand and supersize I installed the EARX into the TiVo Premiere XL. It appears everything works correctly, all my programs transferred, and performance is great! The Premiere XL now reports 318 hours (currently 49% full). Soft restart works fine. Thankfully the drive is actually surprisingly quiet, about the same as the OEM drive, AFAICT. Overall I'm super happy with this upgrade... Donation forthcoming to Comer later today!