I had a 14' with round chines that rolled a little, but not too bad, especially when loaded with batteries, fuel and especially another person. Ran through heavy seas amazingly well. Had a front platform with seat that was decent, except when in rollers. When rollers were present, I would just stand. Much easier to stay balanced that way.
I currently have a 16' with hard chines that is very stable, empty or full. Hits pretty hard in chop or waves.
I recently got a super-light 12' with round chines that rolls a bit. It's nothing too bad, just noticeable after getting used to the 16'. I have not tried it with much gear or equipment yet, but balanced weight always helps small boats.
Size and weight are the biggest factors, but hard chines and reverse chines definitely help when it comes to stability. They just tend to ride hard in a chop.