Hi, Joe,
I agree with you that using "way back" does add flavor to an exposition. I noted your use of the phrase "way back" in your recent essay entitled Writing well in English no guarantee of speaking well in English.
In the last sentence in your post, part of which I quote here:
"... I wrote the essay below—rather harshly and dismissively, I regret to say—in my English-usage column in the Times way back in 2006."
I think you used "way back" correctly, in that the event (writing the essay) now seems like it happened ages ago to you because you now regret your dismissive and harsh tone. There are still instances, however, where using "way back in" instead of simply "in" seems to me to be verbose. I think using "way back" provides some kind of telescoping effect. If I see that phrase, I expect to see somewhere in the sentence or paragraph immediately surrounding the phrase some reference or hint as to why the event is considered to be something which happened "from far in the past" or "from a much earlier time". If there is no such reference, I feel like I am missing the point of why the writer used "way back". In your sentence, as I said, the idea is complete because there is an element of regret.