The analysis is great, but before you all condemn me, remember that I said "if the video was taken without seeing the ball". And I did say that both swings were not poor - quite the opposite, they are both well grooved swings. They obviously are both top shelf pros, for years now.
But let me ask this:
Can you name me one top 100 swing coach, starting out with a fairly new golfer, or even a fairly aged amateur, who would endorse and/or install the huge S loop that is in Furyk's backswing? Or would they try to get you to take it out?
Would any top 100 teacher endorse the over the top swing of Watson in an amateur? Or would they try to get you to do more of a traditional swing, and eliminate the huge slice that often accompanies Watson's ball flight?
My experience, after filming myself, was to see an over the top swing much like Watson's. Not his power, obviously, nor control, but I did have his fade and slice. When I tried to correct it, I could not do it by myself. The pro I visited in the simulator made the minor adjustments to my stance, arms and body turn which brought the club down on the backswing just enough to eliminate my slice, and add distance to my shots. As a matter of fact, I now for the first time in my life have a baby draw on command as my usual shot, and if I want the cut, I simply let the club rise back to the top a bit, and there it is, like magic. I used to do a lot of grip changing, and hooding or opening the face, but not anymore. My only remaining problem is sometimes I have too much draw or pull - I have to watch out how much I drop that backswing.
Both Furyk and Watson outstanding professionals who have grooved wonderful swings that work for them. But my point was simply...I do not know of one teacher who would try to have any student emulate those swings, unless they came to that teacher with them intact, grooved, and hitting the ball very well before the first lesson.
Dat's all I was sayin'!!