It unlocks a watch once you complete all the story missions that give you bonus stats everytime you level it.Bought it.
I really just wanted to get some fresh content and go back to New York. Its a great game for set piece firefights that don't end very fast. Some of the bosses get a tad obnoxious with the health and armor creep as you hit max level and start doing tougher stuff but up to that point I really enjoyed it.
I liked constantly upgrading to new guns and always trying new stuff. Keeping up on all the other gear can be annoying, I enjoy the mod system in the game for the firearms. Lots of gear tuning you can do also end game with the bench that lets you store talents and specific attribute boosts also. Thats kind of where I fell off though.