I'm also very interested in any more knowledge about intake valve deposits on direct injected cars when changing the oil too early as I've done this a lot. Other than the first and 2nd oil changes, I've yet to even make it to 3k miles on an oil change on my 2.3l direct injected turbo. My oil is pretty black on most oils after only 1k miles. And after hearing from a known "expert" that does oil analysis for a living about even M1 0w40 only holding up for 1k miles in a direct injected turbo (I think Audi, though not sure) I've been kind of frightened off of long oci's a bit. Well that and I love changing my oil and trying different oils. A lot. I change my oil pretty early, whenever it suits me really. But most changes are around 2,700 miles or less.
But this new info is making me reconsider. I'd love to hear more about it, even if it's only speculation at this point.