My friend has the DirecTivo setup. What convinced me to stay away from that, for now, was:

1) I already have the Replay. And though I'm a little miffed about the channel change time everything still "works."

2) Tivo (at least in my area) must download the program guide from the satellite everytime you wish to view it. (replay channel guide fast, changing channels slow.... Tivo channel guide slow, changing channels fast.)

3) I don't have any HDTV equipment so the better picture quality of the Tivo isn't that attractive - yet.

6 of one, a half-dozen of the other at this point. I DID get the triple LMB dish to allow for HDTV in the future. I'll probably change then.