I recently ported my app back to the old Javascript API; I wish I could say that it was for the superior older documentation, but it was actually because the new API randomly stopped returning my calls from time to time.

All of the big moneymakers' apps are built on the older stuff, so I figure when it breaks, it gets a bit more love.

The documentation is still shoddy, the Bing-powered documentation search is abysmal, and when things don't work I don't understand why. I'd have happily paid a few hundred dollars to be part of the developer program and have a contact over there, but they killed that. Ah well.