I look at the cue ball last and play pretty decent, as do others that have been mentioned (Rodney et al). I just learned that way on my own as well, find it very eerie for some reason to be looking at the OB when I pull the trigger.
I do look up at the OB during the backstroke, as do most who say they look at the CB last. Generally people will look up during the pause in the backswing or near that transition point. You just need to guard against lifting your head as well, especially on longer shots where the OB is not in your near field of vision.
That being said, most people do definitively look up at the OB before starting their backswing, and that is the generally accepted way of doing things except on certain specialty shots. The CB will just get in the way of the stroke, and looking up at the OB can give you a strong sense of target. You also don't want to dwell on the CB too much since you want to see what happens to the shot so you can feel that mental computer and make future adjustments etc.
As RWOJO stated above, most people use the analogy of shooting, throwing a ball, etc. I counter with a different analogy - hitting a tennis ball with a racquet, or putting a golf ball. In both you are making a swinging motion with the object in your hands and trying to strike a ball to direct it somewhere specific, and in the case of golf the ball is also stationary as it is in pool. You can look up at the hole when putting - that's a common drill used to fix some issues - and the ball will get in the way of the putter, just like looking up at the OB last in pool. It's interesting how these two precise activities evolved into two different standards.
Scott