(ie how often to I have to sync if I want correct listings)?
I don't think that is a fair question, the correctness of the listings probably depends more on the station then the remote. If the station makes changes to the line up (and passes out the information) the day before how is it Harmonies remote. So there is two things, 1) how often does the station makes last minute decisions. 2) does that information get passed down the right channels (I have no idea where local papers, satellite, Tivo.... get their info, but I am sure there must be some database somewhere, and I assume that is where Harmony gets its info).