350 would test it for sure.
I got mine when I weighed 215. I put a trolling motor, battery, and tackle and it worked without trouble. BUT I don't think I'd been comfortable putting another hundred pounds in there with me.
My little boat is awesome. I use the trolling motor to cover distances and then slip around trees and bushes with a paddle. Opens up a lot of areas I can't reach wading, and I can launch it anywhere. It's been a God-send with all this high water. They're definitely worth their cost.