We used a MNIII a few years ago for a party of three men (total weight about 550). We didn't have any problem with the fishing. We did realize very quickly that care must be taken in loading the canoe. We had to keep all of our packs as low as possible or else the center of gravity became too high and the canoe was only marginally stable.  A few times we paddled from a kneeling position to lower the CG. And we encountered a few bends in narrow streams that were too sharp for the canoe's length, so one or two of us had to get out and help it around.