Pros
If you love baseball, it's hard not to love walking into an office covered in baseball stuff each morning. The people are generally very nice and are willing to help out on various projects. There are many perks for working at MLB just like working for any other league or team which include attending games and freebee promotional stuff. The office is also very nice considering it occupies one of the highest floors in a beautiful building on Park Avenue.
Cons
Things generally move very slowly at MLB. I'm not sure whether that's because it doesn't feel like a real company and more like some other type of organization, but there doesn't seem to be an urgency to things. Also, the company is slightly dysfunctional. I always felt like the left hand didn't exactly know what the right hand was doing, which created a lot of confusion for managers and employees.