The first time I watched Rob Roy, I was also disappointed. I too felt it was anti-climactic, and that it had a lot of wasted potential.
The second time I watched, less than six months later, boy did I change my mind. All the potential that seemed wasted before was, in my opinion, fulfilled in a great film. No, it's not as mind-blowing as Braveheart, but it is a great story about one man who valued his honor above all else, and what it cost him to defend. I hope to be as honorable a man as the Rob Roy presented in the film.