That's an interesting point, let me say two things.
First - I wouldn't jump directly to that conclusion. I said these things had to be in balance. There are other ways to get good acoustic performance.
I'm not saying you don't make tradeoffs against those things, but it wouldn't be correct in assuming we made noise
Second (and you corrected yourself) people use the box for a lot of media functions. I think it would take a beating if we were even close to the noise level of the 2005 360.
As I remind people sometimes. We have a console that is roughly 8x - 10x the performance of last gen, depending on how you define it. It's in a case that is only ~ 10% larger than the launch 360. And yet it's quieter than the 3rd major revision we did 7 years in.
Can you comment on the multiplat performance X1 vs PS4 vs PC and/or the 12GB RAM rumor? Are devkits having 12GB?