I actually left before 2012 when it was CSI. The pay was good and the people interesting. Made a lot of good friends and still keep in contact with some, even after several years. The work was interesting for the most part.
Cons
The company is a bit top heavy, but most other companies are as well. A few middle managers made things unpleasant for a time, but they are gone now. Otherwise I would say CDTI is a nice place to work.