It’s true that one’s experience of a university as an undergraduate vs. as a graduate student can be quite different.
Nevertheless, often the latter may still be able to make some valid observations about the former.
I’ve seen cases where they were off base though.
Here is a prior CC thread where some actual undergraduates discussed their perceptions of Columbia, so it is without that potential to be “misleading”, per #2. A few years old, but not altogether ancient
http://talk.qa.collegeconfidential.com/columbia-university/1041703-4-years-later-reflections-of-a-columbia-college-senior.html