I thought about this same thing over the winter.

After looking at newer vests and considering all of my options, I decided to keep my old Mossy Oak vest (20+ years old now) and get a backpack with a hydration reservoir. My decision was easier when I found a few Timberhawk packs on clearance for $5 each at Walmart. These packs have the quiet cloth and some pockets, so when I decide to run and gun I'm just gonna pop in a diaphragm and grab the pack. Now that I've recruited my son and wife, the packs also give me the extra space I need to mule bottled water, snacks and anything else needed to occupy 3-4 hours of time - much better than my vest. I also bought 2 packs, so I'm not the only mule

As for sitting, I typically go prone whenever I'm in a field, but I can honestly say that my lower back and legs have thanked me for almost 20 years for spending $10 on an HS Strut Seat:

https://ads.midwayusa.com/product/57...Strut-_-578234