About an hour ago I asked a question. That was taken as a "primarily opinion-based" question in accordance to the first comment.
Initial title was "Is additional 3% of sRGB coverage and 3" worth additional 150$", so yes it is sort of primarily opinion-based. But essentially, everything in photography (IMHO) except pure technical aspects is opinion-based.
So, probably the words "opinion-based" are not correct in general? (By analogy with Stackoverflow I suppose that it is one of the reasons for question closing on this site).