Are you looking at the 2007 Langsters? According to the geometry charts for 06 & 07, the base model 07 Langster seems to be a new introduction set up for commuting. It comes with 42 x 16 drivetrain, slacker head angle, longer chain stays and shorter cranks than the 06 Langsters.

Specialized site doesn't say much about the 07 Comp but it looks exactly the same as the 06 Comp. The Comp is really set up for the track. Since the Comp has a 48 x 16 drive train, it may be a bit high of a ratio for folks that ride in hilly areas or are not a moderatly stronger riders.

The 2006 base Langster is the same frame as the 06 & 07 Comp according to the geometry chart.