Pay was not "competitive"ly great prior to acquisition, pay will get much more difficult post-acquisition due to being under a larger company
Health benefits prior to acquisition were awesome (free healthcare), post-acquisition - have to pay ~$25 - for health care options
Lack of transparency from upper management (direct management all the way up to executive team).
Actions are greater than words, follow through on your actions, don't just mention or say something, but commit to it.
Personally, I was firmly not able to get a transfer into the team that I wanted to work on, after asking for three years.
Lack of proper management support, especially in the IT Department, for 5 years, was a bummer. Huge bummer.
While I enjoyed my time here, I faced hurdle after hurdle in situations (to the point that I was having to champion myself more and more - and wasn't being supported by a management leader for improvements that were needed) and when leaving it felt like I was more or less just shuffled out the door versus working with me to set up a transition plan that would work for the business and the company to be successful worked out. I didn't have much (if any) communication with upper management rather than just providing ways to improve to them about significant issues that have happened. Beyond that, the discussion that I had when leaving was "Yeah we are hearing that a lot".