A little less seaworthy on big water. Waves can break in as there are no decks. Even among pack canoes there are various hull shapes. I have a Placid Boat Works RapidFire. I use it in the Everglades on the Gulf of Mexico…( till the waves exceed three feet).
At 23 lbs its not hard to portage if necessary. Another disadvantage is the slight increase in windage. Even though the sheer is cut down compared to a typical canoe , they have more windage than a kayak.
Outfitting goes from awful to pretty sophisticated with sliding seats.
I have paddled mine on Lake Superior but when I do I keep a keen eye on the waves and am pretty conservative compared to doing three mile crossings on that lake with a decked canoe and six foot seas. RF isn’t meant for that.
Shouldered tumblehome seems to be a great way to help keep waves from breaking over the sides.
If you went to Lake Champlain though there are people that use pack canoes to cross .Not the little 12 -13 footers but 15-16 footers with more volume.