Yes, on my 500d, MOST of the settings can be altered in a matter of 2 to 3 secs. But ofcourse if the subject moment has passed that quick theres nothing we can do. I dont think even the big cameras let you do it under a sec.
It all boils down to practice too. A new user who looks at the menu and wonders where the ISO setting is obviously going to take some time getting it. I know, because i used to
. But when your really used to the menu. Its almost a subliminal action. After all holding a button and turning a wheel isnt all that tough.
Yes maybe on the more pro models you might do it in 2 secs as opposed to 3 secs. But whether that validates the 4x cost is a matter to consider.