I suppose this is just my problem, but I figure I should point it out.
Ever read a really good book? A page turner, one you can't put down until you've finished it? Of course you have, unless you despise reading, in which case you can leave now, this isn't for you.
Now, have you ever gone back and reread the book? Not often, I bet. The frenzy of that first read isn't there the second time through, and you start spotting the flaws in the story (unless it's really good, and that does happen). Your enjoyment of the book drops because now you see it for what it really is, and perhaps it isn't that much worse, really, but compared to the first time. . .
I suffer the same problem, all thanks to my method of comic reviewing: I read the ENTIRE archive, THEN review. I call it Archive Tunnel Vision, and it basically involves missing some important element that makes or breaks a comic, a failure to see what's going on with the comic and only focusing on getting through the story.
I've had it happen a few times, the most prominent being Jack, which is where I invented the term, and The Devine Dramady, which is an issue I'll get to when I post the review for it (it's kind of embarrassing, actually). I read those comics so hard, so fast, that I failed to grasp that they weren't as good as I thought.
Jack, I caught very early, as I had some time AFTER I read the archive before posting the review, so I actually reflected my sentiments of "it was better the first time." It remains a reminder that I do need to take a bit before I post an especially glowing review. My review of Girl Genius needed this, as it is a very manic comic and without the break, I might have gushed on it too much, though it did deserve a lot of gushing.
The other problem it creates is a false sense of speed. ZAP!, for example, is updated weekly and has been for years, but I clawed through the archives in about 3 days, so it FELT faster than it's published. Now the comic simply DRAGS (now a valid complaint about the comic, incidentally). Other comics face similar problems, the pacing of a comic is, if the comic isn't updated, feels right, but once it slows down to a regular update speed it doesn't feel right any more. This is a lot of the reason you'll see a lot of short comics, rather than the long, decade+ comics here, I don't want to be thrown off by the speed of the comic.
So why don't I read a comic at its own pace? Because reviews are already on average 6 months apart (not kidding about that, BTW) and I don't want to wait a year an half to decide if it's worth the effort.
The Wild Webcomic Review is supposed to be fast, a quick jaunt to decide the worth of a webcomic. Further down the line I might give a final verdict (and you'll see that in my updated thoughts for each of my older reviews), but the the initial review is just that, my initial review. Still, I always keep Archive Tunnel Vision in mind when reading a comic, and try, hard, not to let it interfere. I'm not trying to make excuses for giving positive reviews to mediocre comics, but I do hope you understand the reasons that created them, and avoid the same problems yourself.