I suppose this thread could have gone in the more active Roamio thread, especially since I have both, but I'll give it a try here, although the answer is probably the same across all Tivo platforms. I like to manually look through my guide Sunday mornings and have noted if the guide has updated quite early Sunday morning, say 5am ish, if I do a manual update at say 10am, it downloads quite a bit more information. As I no longer have dial-up I can't go off how long it takes to download the guide, as it only takes seconds, but I go off how long it takes to load my download, which with a larger download can take several minutes. What I've noticed is if the automatic update was say at 9am it only takes a couple seconds to update the guide, telling me not much if any was changed, leading me to believe major weekly updates might be done at say 8-9am ish Sunday morning?? When I manually look at my guide for the upcoming week I like to have the most recent updates and have noticed if I go at say a 5am download not all of the weekly talk shows have been updated with what stars will be on the program, if I download at say 10am Sun AM it seems most have been populated for the upcoming week. Anyone know?