There are plenty of things to be said against the email interview: it lacks tone; it's not spur of the moment enough; it's just plain lazy. Yeah, but no transcribing! No dealing with actual real people! I say that it's a treat.

I, however, am not usually correct. Donna Talarico at Absolute Write discusses why person-to-person is best:

True-- you can get a hint of someone's personality through reading what he wrote. But in a set of interview questions, there is not much you can gain in the way of telling a subject's personality. Does he laugh a lot? Does he smile a lot? Is he animated? Aside from his personality, how does he look? What is he wearing? Is he wearing a favorite hat? Maybe there is a story in that! These are all wonderful things you can describe in an article. In my article about Mr. Butler, I painted him as a wise old man who smiled often, showing years of laugh lines. In addition, Mr. Butler did cough and clear his throat many times-- he has asthma. He's also 86 and very frail, so I was able to bring that in, which lent itself very well to the whole story of him preserving a legacy-- but also that he was ready to take his own spot in history.