Compact doubles make so much sense it's scary.

The number of people chiming in here who have them, and the number of club riders I know who have gotten them in that last year attest to that. For any middle-of-the-pack club rider (who, let's face it, make up 80% of road bike customers) and many others, they are the obvious choice.

So why is it again that Shimano still doesn't make one?

I don't have one yet (although I do have other 110/74 cranks), but I'm getting the Centaur.