Pros
Acquisitions of smaller organisations every month shows a relentless desire to grow. Strives to be market leader in every sector they operate in. This can lead to the opportunity to work around the world on 3 year postings, gaining knowledge and experience along the way. Good company for a short term CV builder, but I doubt you will stay there much longer.
Cons
If your company is acquired, you will be assimilated into the AC way. It has worked for them, so why change? Ultimately this will lead to your company becoming little more than a brand in the AC portfolio. They promote from within the existing empire and will use their proven model regardless of how innovative yours might have been. Management is distant, detached and disengaged from the workforce, heavily driven by numbers.