Pros
Opportunity to work on a variety of projects at one time. Valuable experience with numerous mouse models. Great technicians. Beautiful new facility (if you've ever worked in academia, the money they've poured into the workspace and equipment will make you swoon). There seemed to be a few recurring problems when I was there --holes in the training program, lack of accountability for certain areas of management, lack of transparency/communication between coasts, meetings to decide when to have a meeting to schedule the next meeting--but a new "no nonsense" manager seemed to be picking up the pieces just as I was leaving.
Cons
High turnover. Work/life balance can easily shift toward work. Difficulty retaining a lab manager. Restructuring of management's reporting structure every 6 months that seems to result in a confusion of who is responsible for what and tasks (mostly training and oversight) get skipped entirely.