I've been letting my TiVo "bed in" past it's latest update to 3 tuners, and on the whole I'm happy.
However I do have some gripes with my TiVo. So far it's crashed on me twice with a circle image spinning round just by pressing the "My Shows" button. Also I missed the Royal Wedding, for some reason (I still havn't figured out why) my TiVo stopped recording about 1 hour 30 minutes into the coverage.
I can forgive a single blip in recording, but the hanging at the circle annoys me the most, once I had to take the power lead out of the back of the box (I wasn't happy to do this, I could hear the hard drive heads crash when I did it) and the other time I decided to leave it, which it eventually clicked back in (not to the My Shows screen though) to the main menu.