I have the .50-70-750 of his, and it is a real handful with full loads. In the Contender the large bore means that the barrel is very thin and light, making the entire pistol lightweight. It's too thin to mount a scoppe, so no weight gain there.
The FMJ bullets aren't so bad until you exceed 1100 fps with them. My hunting load is a 475-grain RCBS bullet hollowpointed at ca. 1375 fps. That one hurts! I can only imagine the .50 Alaskan... :-D