Pros
Electroimpact gives lots autonomy, it was my first engineering job and in just 3 months I was designing assemblies for a production machine. If you're a new engineer hungry for some design work, this is the place to be. You get purchasing power for all of your parts and equipment, there's a generous profit sharing program, the benefits are great, and the facilities are excellent. I was only there 2.7 years, but I've got a portfolio loaded with designs that I expect to serve me well in my future job searches. I found that passing the FE exam adequately prepared me for the EI exam. There's extreme transparency, everyone can see everyone's wages and parts. The engineers there are generally young and friendly, I never had a coworker I disliked. You get lots of latitude to come, go, and work toward overtime bonuses as you please. They're got an ABS 3D printer that's useful for home projects.
Cons
As a caution, you have to actually like engineering to excel there. If you're someone who just got into engineering for the money or parental pressure, you're better off going somewhere that will mentor you. EI is a very self-directed place. I'm not the only guy to get a blind-side layoff with a couple hours' notice.