The width of the Utility Belt is 5” and the Comfort Belt is 4.25” In general, the Utility Belt is more robust and is built to carry more weight while the Comfort Belt is built for comfortable wear and carries only small essential items. The Utility Belt can carry a Body Bottle 500 in the rear pocket and has trekking pole loops. The tradeoff is that the Utility must be much less stretchy than the comfort belt in order to support this much weight so it’s not as comfy and is a little more difficult to get on and off. The comfort belt will carry a phone/keys/credit cards and other small items, but it will not support the weight of a bottle.  It is, however, super comfortable and user friendly. The short answer is if you want to carry water in the belt, go with the Utility Belt, and if you do not have a need to carry water, I recommend the Comfort Belt.