Pros
The people I worked with were generally very nice and willing to help. Safety was a huge thing which was also nice. Large, established company so wide variety of projects to work on. Benefits were slightly above average.
Cons
I was constantly paranoid about having non-billable time. I'd routinely be "at the office" for 8-10 hours and have 6-8 hours of billable time because of small gaps between scheduled stops at projects. Pay was pretty much terrible for the technicians. Which was ridiculous because they generated more revenue than anyone else in the entire company. Project manager once asked me to bill mileage for project A to project B, which I visited later in the day, in order to stay under budget. I didn't do it but also didn't report it. I think this incident was an anomaly but still worth a con. The office I worked at took way too long to get rid of toxic employees.