I remember a time when a vest was pretty much the only option. My problem was that I could rarely easily find what I needed even though certain flies/boxes were in certain pockets. I just seemed to always pack just too much gear...extra spool and line, too many fly boxes, too many floatants and sink, thermometer , hook remover, pliers for turning down the barb, leaders , tippet spools, jack knife, rain jacket, Candy bar...it was endless.
Then I switched to a Richardson chest pack. I had so many flies stuffed into the compartments that I couldn't pull out a single fly with pulling out a bunch. This year I tried a William Joseph Mae West type whatever you call it and really cut down on the number of fly boxes etc. I have made up boxes with only a half dozen patterns that should be on the water. It seems to be working but I still have to get used to the figure I cut with those two big pockets sticking out in front of me like they do.