I'm using moderation instead of captchas to police comment spam because 1) I hate captchas, and 2) I really, really fucking hate captchas.
Generally, I turn your comments around rather quickly, because notices go to my email, which goes to my phone, which I (almost) always have with me.
I have, however, noted a couple of quirks in the system. One is that notices sometimes get "threaded" in Gmail, which means that if several come in in quick succession, I might not notice the one in the middle. I think this has happened a couple of times. I've made every attempt to rectify that. The other is that if you hit "publish" (even inadvertently) it is going to come to me. A couple of times there have been clear cases of double posting, or of an incomplete version of a subsequent comment coming in. Here, my guideline is common sense: if it is obvious that the second comment says what was intended (but incomplete) in the first, I just publish the latter comment.
The second scenario is the only time I have knowingly deleted/neglected to publish any comments. I'm not saying I'd *never* refuse to publish something here (other than spam), but honestly, you'd have to say something pretty horrible. And if I did, the fact of it and my reasoning would be acknowledged in that comment section.
In case you were wondering.