Of course busy people do the most. If you're busy doing stuff, well, you should wind up doing the most. Life isn't exactly a volume based competition, of course, but it's nice to accomplish things. I'm not talking about people who are busy in a cliched sense, the way we are told we are all so busy and therefore need to grab dinner at a drive-through window tonight. I'm talking about people who are busy because they are always trying something new, always learning a new skill.
I suspect that the best books--or at least the best first books--are written by those with the least time to write. Taking time from your television viewing to write a novel, that's pretty easy, but you may not have much to write about other than what you like to watch on television. Taking time away from your small business you run on weekends and evenings and the graduate courses you're taking on the side, that's hard--but you sure do have some great subject matter to use.
Yet these busy people are the ones who seem to write the books and found the companies and do most of the truly cool things in life, even without stopping at the drive-through.
It pays to get busy.