Well if you think about it,
The install does not have to connect to the Live servers to verify an email address and password,
It also doesn't have to sign you into all of the preloaded services
So the spinning wheel is shortened quite a bit for us mere mortal on pretty much dsl
Beside I use the custom install anyway and uncheck allot of items that are checked search.....
Also it's the fastest way to be directed to a local account and that's the real point,
Yea sure you still have to get a third party driver and any offered win updates but at least it streamlines one process the basic install.