Good Call, ChadTower, I think you might get into some hot water for even trying to upgrade a cable box, because most of them are rented, you don't own them. Check your bill to be sure. It'll usually have a 5$ or so fee for "Cable box rental" or similar.
BTW, the link to that post was excellent. I'd been considering FIOS, but after reading that, I'd definitely not even bother with their DVR and just go with an HD tivo. Good info.
Thanks!