The lack of confidence in the guide is the single most important issue that prevents me from ever buying anymore TiVo equipment again.
I agree. My first TiVo was a Series 2. I turned a number of other people into TiVo fans. I'll never buy another piece of TiVo equipment since the guide data is so bad now. I don't like having to babysit my "to do" list to make sure what's supposed to be recorded is scheduled to record. I just went to play two shows that recorded yesterday and neither of them was what TiVo's guide data said would be on. I nearly missed Ru Paul's Drag Race Untucked on Friday because TiVo claimed it was an episode from two seasons ago instead of the current season (it wasn't). The same error is in the guide data for next week's episode. Whenever I have contacted TiVo in the past to report guide data issues -- sometimes an entire network will be incorrect, presumably showing things according to a different time zone -- I have never received a response or resolution.
Apart from my issues with generic guide data for shows like The Daily Show 15 years ago, forcing me to set manual repeat recordings, I could rely on the guide data when I was a new TiVo customer. Now I feel like I have a high capacity, hard drive based VCR that I need to pay attention to on a daily basis to make sure it's going to record what it is supposed to and not record stuff it isn't supposed to. It's particularly galling because I can find the correct program information on other websites; the people compiling TiVo's guide data seem to just make up some of what they list. I highly doubt that
any source actually tells them for a new show that some episodes are from two seasons ago.