i do leave concrit, yes, because i think it would be dishonest to leave that out and only say what i liked about a fic [well, if these things really bothered me]. i feel that most people appreciate if you mention what didn't work for you as a reader. i don't leave comments on stories that i didn't like at all. of course there are also stories that i adore 100% and i don't hesitate to say that :).