I worked an internship at ADEX Technologies this summer and had a wonderful, instructional experience. I came in with a Math/Software background and was given projects that incorporated my skill-set with new fields that I had little prior experience in. This really helped me develop as an engineer and both the CTO and COO were always willing to help and give guidance from a high level all the way down to the actual code. The office environment was relaxed and friendly and all the other employees were extremely helpful.
Cons
I really can't think of any. The only tedious part of my day was the I-95 commute, but I was able to shift my hours a bit and bypass rush hour!