Wow, what a contentious question!
I carry a chest pack that I've rigged to pair up with a Camelbak. The backpack offsets the weight from the chest pack, making it much more comfortable (I hate having a chest pack hang on my neck all day) and I always have plenty of room for beverage, food, extra clothes in back and fishing gear up front.
In the end, it really doesn't matter. Catch fish. Have fun. Keep the river and the Park clean. Help other people. Those are the things that really matter!
I got no style, I'm strictly roots.