Hello, I currently have a Series 3 HD with 2 TB. One is internal and the other is an eSATA external via the WD MyTivo Expander. [media]http://www.blogcdn.com/www.engadget.com/media/2009/04/4-22-091tbdvrex.jpg[/media] I originally used MFSlive to "marry" the two 1 TB drives and have never had any issues with my Series 3. I am now going to purchase a Tivo Premiere XL. I plan to replace the one internal 1 TB drive with a DVR Dude 2 TB internal drive. Once this is done, can I still add the eSATA external 1 TB MyTivo DVR expander that I used on the Series 3? This is supposed to be a "plug-in-play" add-on drive and it'd be cool if I could have a total of 3 TB (2TB internal,1TB external) with my new Premiere XL. Let me know if this can be done, or if you have any recommendations. Thanks everyone.