Re: What's in your vest?
In addition to extra leaders & tippet material, and of course fly boxes, I carry a small hand towel, a mini flashlight, a multi-tool or multi-function Swiss Army Knife and never carry split shot, as I don't use it. I found a forceps/scissor combination online a few years back, believe they may have been from Cortland.
However, the majority of the fishing I do is warmwater & saltwater, so I carry a pair of heavier long nose pliers on my belt too, primarily for bigger size hooks that the forceps don't do well with.
I don't usually use the retractors, as I've broken or lost too many of them, or they hang up too easily in some places I've gone. Not as convenient, but I prefer to have everything in a pocket.
Remember, no one likes to be behind the big truck, but that's better than being under it!