depends on what reciever you get, i know the new HD tivos are having issues, but you need it to view mpeg4, which dtv is going to in the future (all local HD is mpeg4)
i have the hr10-250 HD Tivo and like i said i really havnt had any major issues with it being slow. Tivo started the DVR craze and im sticking with it, lol. Im afraid to get the new reciever as tivo is no longer on it, just dtvs dvr. catch 22 for me in the future.