Love em. I have the Freestone pants, and the Headwaters chest waders. The Freestone have been flawless, but aren't Goretex. The Headwaters are 3 layer Goretex, but I tend to wear the Freestone pants more often just because I generally don't wade chest deep that much. Also wear them when kayaking in cooler weather. If either eventually fail, I'll get a pair of the G3s. But they are still going strong for 3 years+.
I do wear them when I duck hunt. Just add a base and mid layer pants, and you should be fine. Looks like they do make them in 3xl and they also do custom sizes, but you'll pay for that. Simms customer service is also top notch.