Pros
Some cool people working there in low level positions, but after a while you just start to feel sorry for them, as they're never going to get a chance to move up or learn anything new. When they are no longer relevant they will be laid off.
Cons
I worked for a company that was acquired by Marketwire. Most of our team moved over to Marketwire following the acquisition. Why wouldn't we, after all, we loved our jobs, but from the first day following the acquisition, we could tell that the energy we had for our jobs was going to sucked out. Within one year of the acquisition, all but one member of our team had left Marketwire. So it wasn't just me that had problems with the new culture. We just couldn't adjust to the poor working environment, lack of enthusiasm, and overall depression of working there.