The strength of new Tigers acquisition Gerald Laird is supposed to be his defense. Catcher defense is still one of the most difficult things in baseball to quantify but let's take a look at the available data to see what conclusions we can make:
The running game
Data from The Hardball Times say that base runners attempted .87 steals per game against Laird in 2009. That is worse than the league median 0f .68. In 2007, the steal attempt rate against Laird was .89. The good news is that he has been successful at gunning down runners - 27% caught stealing percentage versus a league median of 22% in 2008. His CS% was 38% in 2007.
According to THBT, Laird made .096 errors per game versus a league median of .054 in 2008. He made .109 errors per game in 2007. According to David Pinto's Probabilistic Model of Range, Laird's range around the plate was almost exactly league average among catchers in 2008.
Going back to THBT again, Laird allowed .43 WP+PB per game versus a league median of .36 in 2008. His 2007 rate was .38. Using the pitch blocking data provided by Beyond the Box Score, Laird had an 85.5 block percentage on balls in the dirt with runners on base in 2008 which was almost precisely league average.
Fan Scouting Report
Looking at the 2008 Fan Scouting Report, Laird was give a 62 out of 100 rating in 2008 and 61 rating in 2007. That means the Texas Rangers fans thought he was pretty good defensively. They game him especially good marks for his arm strength and accuracy.
His 5.21 catcher ERA was worst in baseball among regular catchers but I doubt that means anything. Arlington Stadium will always produce a ton of runs regardless of who is catching or pitching. There is really no good way to quantify game calling at this time.
Catcher defense is really difficult to evaluate and even some of the above data could be heavily influenced by the pitching staff. One thing that is clear is that he does a good job of throwing out runners. There is no evidence that he is especially good at any other phase of catching. It does not seem as if he is an elite defender but the fan report is encouraging.