I have used Water Masters many times and find they are quality built hulls, stable and will safely get you down the rivers you mentioned without any floatation problems.

You are sitting low on the water, they are slow, and blow around in the wind more than most pontoons. The one weak point is the oar system and you need some spare oar lock parts with you at all times. The oars are also too short.

It is really about trade offs on performance vs. travel friendliness on a Water Master vs. a quaity pontoon.

Most important though is to get a quality watercraft that will get you down the river safely. The Water Master will do that.

Good luck on your selection