Bob, I haven't paddled or ever seen one of these canoes, but I can form an negative opinion to your 300 pound tripping question just from their specs and pictures.
Both models have a 12" center depth, which is too shallow for heavy tripping loads in my opinion. The larger Willow is stated to be "for general pleasure and light tripping, or set up for Freestyle paddling." Freestyle canoes typically have shallow depth for the specific purpose of being easily heeled to the rail, and I don't think 300 pounds constitutes "light tripping".
Look at the pictures of the empty smaller Wisp with the slim girl paddling it. There's not much freeboard even with that tiny a load.