Pros
Probably depends on location but the staff I worked with were friendly and welcoming when I was first hired. Another pro is that DLR Group wins a lot of projects so there is usually a laundry list of tasks to complete.
Cons
With the acquisition of multiple firms and over-hiring you get lost in the mix and instead of being a name you become a number. As others on this thread have mentioned, you are expected to work over 40 hours a week for only 40 hours of pay. The young and fresh inexperienced employees right out of college are eager to meet that goal so it sets a level of expectation because they are trying to make a name for themselves. As a result they are promoted to a reward-less title which forces them to have to invest further into the company. Management also does not defend or step up for their employees, they just allow the corporate structure and numbers based game to dictate the status of each employee. It has a very "just doing my job" feel now and wasn't the same firm I was hired onto. Lastly, there are no annual reviews and typically if you aren't asking for a raise, working over the 40 hour threshold, or being "promoted" then you do not receive an annual pay increase or even a performance review.