I'm another one for whom editing happens all the time. I've never been real clear about what constitutes a first draft anyway. In the Olden Days, I think it was whatever you sent off first to your editor, but even then for most writers there had probably been numerous revisions (though I have read of writers who only did one draft before submitting; they let the editor decide whether any revisions were needed).
As for the waiting period, I totally get the argument in favor, but let me offer a counter-consideration. It's much more subjective, but for me it has relevance and perhaps it will for others.
It has to do with being *in* the story. Let that mean whatever it means for you. For me, it means that I care about the characters, any emotions regarding them are still fresh, even raw. The jokes are still funny. The tragedies still tearful. The places are still wondrous, the action scenes still exciting.
Now, when it comes to revision, I don't want distance. I don't want objectivity. I want still to be tangled up in the story and its emotions.
What has happened (again, for me) if enough time lapses, and especially if I've started working on something else, I've lost the resonance. I've also lost the feeling I had at various points that the story might go this other way. Very often what's required in my revisions is improving the pacing, filling in details of a scene, striking resonant chords on theme, and other tasks that require a certain close involvement with the story. If I wait too long, it all becomes objective. Mechanical. I'm not polishing, I'm filing down.
The place where a bit of distance becomes useful (have I said imho too much yet?) is in the little stuff. Consistency of voice (once I've really established a character's voice). Consistency across the board, really--descriptions, dates, all that stuff. It also helps with proofreading, because one does tend to become text-blind and not see those double spaces, form instead of from and related mistakes, punctuation gaffes, etc. Even there, though, you can turn to reading aloud, reading backward, and other proofreader tricks.
But in those initial, potentially big, revisions, I tackle them more or less right away, as per above.