I've posted on this topic many times before, and I don't know what can be said that hasn't allready been said millions of times. Instead I ask that you watch Reyes, Strickland, Van Boening play. Really watch the cue ball. Are they using center only? If you answer yes to this question, you are blind and should find a different hobby.
Saying you should only use (vertical line) center ball is the same as postulating that the shortest path between two points on the map is a straight line, thus everyone should follow the straight line to any destination...I sure am glad I didn't have pool instructors as officers in the army, otherwise I would have surely been lead straight off a cliff, into a swamp or a mine field...
Pool and snooker are very different games, even if some of the princliples of play are similar, the position routes are VERY different. I've talked about this before as well, so I won't go into detail on the subject. I'll just say that anyone who thinks that position play is done the same way in these games is not paying attention. The shots are different, the cloth is different, the cushions are different, the cues are different, the balls are different, heck the table is even at a different height (not relevant here, just thought I'd mention it).