Originally Posted by StevesWeb
Definitely replacing the internal drive is the better choice. With an external drive the chances of losing all of your recordings go way up.
I suggest a 3TB drive optimized for AV use
If you are recommending it for the extra year of warranty, that's fine.
If you are claiming an AV-rated drive will perform any better, than a non-AV rated one, or that it is a requirement, you haven't been paying attention to the hundreds of posts I've made pointing out that TiVo does not make use of the ATA Streaming Command Set Extensions (AV feature set), resulting in any drive you use writing AV the same as regular data, with the same error correction as any old data. Any product literature on AV drives, specifying "streams" supported, becomes irrelevant, when the host and/or host software don't make use of the AV feature set.
Sometimes people want the cheapest route. Sometimes they want the best warranty. Sometimes they are OCD about using an AV drive, because that's the kind it came with. Sometimes they just want the facts.