Agree with the article, and also iwth the other posters and K2's, and Stacie S's comments, 30 minutes is too much differential.
As the article points out, the M and F elite winner are more like 15 mins different, and I think that trickles down and is a good difference. In fact, as you get to the non-elite average runners runners, there might not be none at all - just look at our club and an average runner over 40, we have many women that are on the same level, or faster than the men. so, 15-20 minutes should be max differential, or maybe, how about none at all?
Western States and many others have no differential for women - maybe Boston needs to go that route.