The vest is rally nice. I'll do a quick review. First off yes it will fit large people, but you may need to get different cummerbunds, since these don't velcro down they zip up in the middle.
Anyways, I'm 5'11" and have a small build, roughly 35" chest. They guy I got it from is built and has about a 45" chest, and it fit him, stomach wise the securing strap is tight but it is adjustable and elastic. For the actual vest it doesn't feel to big, not as small feeling as the CIRAS but not as bulky as IOTV's. But still allows for the same amount of protection as the IOTV.
The vest alone weighs quite abut though, 3-5 pounds if not more. Really not to bad, plates are really easy to get in and out, but they are secure.