Porro Prism binoculars will give you better 3-D imaging and better contrast. Roof prisms are more compact and as long as they are phase coated will give you very similar contrast as the Porro. Roof prisms are nice if you want a compact binoculars compared to the porro prism style, but you will pay more. This is my thinking, if you are planning on using them primarily for bow hunting, I would go with a Roof. If you are planning on using them for rifle hunting and you do a lot of "deer shack" hunting, than I would go with the Porro.