We had good experiences during our tour and like the others mentioned: you need to go with your guts. I know couple of friends whose children went on campus visit and didn’t get good vibes and/or totally turned off with the school(s) that they thought were their top choices.
Regarding the tour guide: it could have been this was the first time the student leading the tour, maybe it was a bad day for this student. I would separate the “noise” from the “message”. One tour that we went to, the student was ok, but compared to the others, she was probably on the “okay” level compared to “wonderful” when talking about spots on campus etc, but she was really lively when she explained her experiences with her internships and that was the main selling point of the school: they integrate internship with your curriculum that you can graduate on time even with internships and most students get 2 internships by the time they graduate.
And the goal for a campus visit is not to reaffirm your belief but to figure out whether you and/ (especially) your kid get positive vibes or not. The friends I mentioned earlier: they went on tour to one of the top colleges in the country and they didn’t like it. But I know some did and ended going to school there.