A fascinating and thoughtful thread; thanks, guys. As is so often true here, a lot to think about.
For myself, I can't quite imagine not saying that I enjoy the courses of so-and-so, or don't really like the courses of so-and-so until I've reached some arbitrary critical mass of play. Others will have to decide what weight to assign to my opinion, and it may well not be very much. This is the case with other art forms; I am not a jazz fan, though I have not heard ALL jazz and like some.
There is, however, a line that I probably shouldn't cross in calling someone's work crap or the like. HOW I express my opinion of a body of work here is what Mike was talking about in the first place, I think. I think there is wisdom in NOT saying a lot things that you are thinking, whether face to face or here in cyber world.