Hammer,
It's not fair to look at this guy's career average, and you know it. He's only played 4 seasons, been moved around a lot, and any young player's first season or two will scew the overall career average.
In 2004 with Florida before he was traded, here were his stats:
In only 281 at-bats, he hit 15HR, .270 BA, .388 OBP, made 721 plays at 1st with only 8 errors for a fielding percentage of 99%.
His last year and a half with the Dodgers have screwed up his numbers, because their hitting coach was messing with his plate discipline. Also, Dodger stadium isn't exactly the best park for a hitter.
I'm not saying Choi is a great player, but he has a lot of potential. PECOTA says Choi's top comparison is David Ortiz in 2003. Here are the numbers:
For comparison, David Ortiz in Minnesota over 6 seasons only hit 58 home runs in 1477 at-bats, or 1 HR / 25.4 at-bats. In 2003 with Boston, Ortiz hit 31 home runs, .288 BA, and .369 OBP (1HR / 14 at-bats).
Choi, in his entire career, has averaged 1 HR / 22.8 at-bats, but if you just look at his Florida numbers, he hit 1 HR / 18.7 at-bats. These pre-Boston numbers are pretty similar to Ortiz's.
What's not to like about this deal? This move has high-potential, is cheap, and is low-risk.