The good news is: the HD TiVo seems to be upgradeable. We have successfully backed up and restored the software, expanded it, and added second drives. PLEASE NOTE: We havent yet filled up these drives with HD content. Once weve had a chance to try many other tests in these units (weve got a pretty big list) well try this. So for now, were relying on what we see in System Information. Until we have successfully loaded the drive with content, take all this with a grain of salt. Here are the details: We used our standard backup string: mfsbackup f 9999 1so /image.bak /dev/hdc The resulting image is 1486 MB. We restored to our 300 GB Maxtor QuickView drive as: mfsrestore xzpi /image.bak /dev/hdc and in the TiVo we see 37 hours in HD and 248 in SD. We have blessed drives in noswap and added them to the factory drive, and those drives are recognized by the system. Adding a 300 GB drive to the stock 250 GB drive creates 70 hours in HD and 470 hours in SD. So far, we cant get a dual 300 setup to work reliably, but were still working on it. So in short, we can get mfsadd to work with one drive, and we have successfully added a second drive to a stock A drive with BlessTiVo, but we have not yet successfully used mfsadd (or the x switch in mfsrestore) across two drives, with the first being >250GB. The challenge here is to safely hold the second drive in the unit. Our TwinBreeze bracket wont work in its current configuration and we have begun the process of engineering a new bracket for this unit. Quality components take some time to engineer, test, tool, and manufacture. The power supply in the HD box is 85W so we dont see any reason to add the PowerTrip to this box at present. More details as they come. Michael EDIT: 9/28/04 We have updated our D-I-Y upgrade site to support this model: http://www.upgrade-instructions.com We have a CD with large kernel support, and full instructions for using two large drives for this model.