Pros
Work from home, your coworkers will appreciate your hard work, free junk food (but I don't think of this as a pro since we already sit behind a desk for 8+ hours, free soda and chips is probably not the best solution. Games and contests to keep the slow days interesting.
Cons
I was only employed with MNG for two years. That being said when I started it was a completely different company "Nexgen" merged with MetaPharm and became MetaNexgen, bought by an investment agency and changed to MNG Direct...with 3 large layoffs (that I know of) happening in that time. Job changes, jobs removed and jobs brought back after some time had passed from one lay off. With all the changes at MNG in such a short amount of time I think you see why they have very mixed reviews. Your experience will differ from department to department and depending what department you are in will determine how you are treated. You will do mediocre work for average or below average pay, everything will be a rush, you will work overtime and be asked to do things on your days off, favoritism and sexism will be a big part of your day in meetings and interaction with management.