The big plus for me with strap vests is that they're much cooler than full vests in early season warm weather, and of course they can be worn over layers when it's cooler. I used a Filson strap vest for several years, but gave it away when I found the Quilomene. Since then I've had two others with belts for carrying the weight of the game bag -- a very good Bean with a high back that was too warm, and finally the Pella.
Most of my hunting is for pheasants. I'd never go back to any kind of vest without a belt to put that weight on my hips.
Jay