Well I must go along with the pro-pump crowd. With a pump you never have to wonder if you have enough carts with you. I had 5 flats in one ride once, had I been using CO I would have been up a creek. So just because you never had more then one flat on a ride doesn't mean that someday you won't have more. With carts you have to remember to restock your seat bag or buy more before your next ride, you have to figure out what to do with the empties...most cyclist seem to throw them on the side of the road because I see those dam things everywhere I ride. If your going to use CO TAKE THE EMPTIES HOME!!!!!