My perspective is it varies depending on when I read the story in relation to when it was posted. I know I've left comments on your journal before. You and Maderr, however, are probably the two people whose stories I follow most regularly. I fandom/pairing/story hop like nobodies business. If it was written more than a couple of weeks ago, I tend not to say anything because I don't like to draw attention to the fact I'm reading it late. Essentially, the older the story the less likely I am to comment. Which is why I've never commented on anything in your archives but I've made comments on newer stuff.

As a good example, I'm currently a couple weeks behind on your and maderr's stuff. For you I haven't read anything from Cowboys onwards, I'm just now looking through and commenting on this and doing the polls, but I probably wont get to the reading until tonight.

I also tend to be less likely to read in progress stuff for fear of cliff hangers, so my comments are less frequent with such things.

That said, I'm pretty sure I've said I love your stuff. I'm not sure I actually qualify as a lurker, since I've commented pretty frequently for me.