I really like it too. Upton looks somewhere in the vicinity of league average offensively, can run, is a plus defender on the corners, and can fake it in CF without embarrassing himself. That makes him a perfect 4th OF, who can probably approach 2 wins if forced to play full time.
At 5M, and a prospect worth probably another few hundred grand, that's a nice addition this year, but especially next year when Pillar is currently the only OF under team control.