I'll just point out three things I really like about Murphy:
1. He has put up some crazy good AAA numbers despite being younger than his competition, and he's still only 24.
2. He managed to post a .441 SLG (.731 OPS) with a .220 Avg. That's crazy power for a SS; Crosby could break his back swinging at a pitch and still not have that kind of power.
3. He actually put up better defensive numbers than Crosby at SS, and seems to be perfectly adequate in the field.
Bonus: Projection systems love the guy. As Rob Neyer pointed out recently, guys who hit for crazy power and low average in one year and good average but only decent power tend to figure out how to do both eventually. My guess is that PECOTA will like him about 100 OPS points better than Crosby for next year.