I'm a relative newcomer here, but have posted a lot of images, and I have to say that I'm really glad to get comments of ALL kinds.  I don't like feeling that I'm working in a vacuum!  If something I'm doing isn't working I want to know about it.  The ratings are, well, probably not as useful.  I think many people are like me -- I don't want to leave bad ratings for anyone, I just don't leave anything at all if I feel that the work is substandard.  Maybe that's not the way the system is set up, I don't know.  It's just really hard for me to give a poor rating.  I love looking at everyone else's work; when I see a posting that really strikes me I visit their gallery to see what other lovelies they have to show.  And I have to admit I'm guilty of not giving background information for many of my pics -- no excuse except laziness.  I'll try to be better in the future!  This whole public gallery thing is new to me, and I don't really know the accepted routines, but I'm learning.  I like to think I'm trainable!