indeed.
Well depends on the committee. If they all like the same things and simply going through the motions to make it look like others have a voice but in reality already have their mind made up, then it could be about as swift as simply having one vision if the fluff is dropped. :p
Yeah. I have never seen any committee like that for any purpose. Unless it is just to rubber stamp someone's ideas, there is always debate over something. But that is the strength of committee design, as long as everyone is pulling toward the same goal, you can really get diverse ideas on the table, things one person wouldn't always think of. But it does take longer.