Pros
First off, I'd like to note that I am currently working for Northeast Utilities in a co-op (intern) capacity, and this is my first 40hr a week position out of college. I work out of the NSTAR location in MA. For me, this has been an eye-opening experience. For someone who knew close to nothing about how utility companies operated, I felt like my knowledge expanded in all aspects about the company. My position was primarily recruitment, giving presentations, and job postings. The longer I spent working there, the more responsibilities I was given. Being in HR, I was able to work with managers and employees from both the Gas and Electric fields of the utility side, as well as various manager and employees from our different corporate sections. If you are looking for a company who does a great job with investing in their employees, and provides several outlets for personal and professional growth, I would highly recommend looking at a career with NU.
Cons
With any merger between two companies, there is always some issues with synergy. I have noticed a few problems with getting former NSTAR and current NU employees on the same page with different types of computer software/programs, but it has been improving since I have started working there.