I decided to ditch the vest last year because I am a heavy guy, 5'9' 230 lbs. I sweat with waders and a vest on even in early spring on some warm days, and in summer I suffer. I bought this,
http://www.basspro.com/webapp/wcs/stores/servlet/Product_10151_-1_10001_91536_175008000_175000000_175008000_175-8-0
and it was cheap. It's smaller than some of them, but I can fit a few boxes in it allong with leaders, camera, or whatever. It comes with several straps and harnesses of varying lengths. I stripped mine down to just the shoulder strap, and wear it over my neck keeping it slung behind me.
On really warm days in the spring or summer, I'll even ditch that and just wear my Columbia four pocket shirt and some cargo shorts (see my avatar). I really like to be comfortable when I'm fishing, especially if I'm going to cover a few miles. To me it doesn't make sense to wear a vest in a lot of situations, especially smaller wooded streams where a lot of walking or hiking is involved.
P.S. Now if I could get the Columbia in a sage color I would be set. They do sell them in camo, which I have and do not wear as often because I just feel weird wearing realtree camo when it's not hunting season. I must be self conscious about looking too redneck.