Pros
Con Ed is a good place to work. They generally take care of their employees and are loyal. Lots of opportunity to move around within the company, however being promoted to a manager level is very political (and unfortunately it seems many managers are hired based on their skin-tone and/or gender - not qualifications). Decent pay with some OT opportunities, decent benefits, great stock purchase program. They have started to come around with work-life balance and flexible work arrangements, however some managers/departments still believe you HAVE to be at your desk to get work done. Very stable - you can work here for your entire career - if you can stay awake.
Cons
Typical big company bureaucracy. Work is procedure driven, which disallows thinking outside of the box. Very quick to finger-point and pass along blame - CYA culture. Work can be very slow paced and boring at times. There's an abundance of employees - 5 people to do 1 person's job. Years ago there were people stealing from company/taking kick-backs, so countless accounting measures have been implemented in an attempt to prevent these occurrences and make getting project funds/change orders incredibly difficult.