Pros
I worked for ECS for 12 years, and for most of that time they were the best company I have ever worked for. When a contract I was on was lost in a re-compete, I expected to be let go, but wasn't. A VP took interest, emailed every other VP, and by the next day I had TWO contracts to choose from with the company. They were amazing at taking care of their people.
Cons
But then they were sold to a larger company, and became nothing more than "just another body shop." Every year the benefits packaged changed and got worse. The position where ECS had me placed (for 7 years) was eliminated. That happens of course, but ECS was particularly bad about it. I was called into a surprise meeting by zoom, and told "due to COVID related budget issues your position has been eliminated." I was let go from ECS in the very same meeting. No Thank You for 12 years, and NO attempt to find me another contract within the company. Also no contact from HR about separation. I had to chase the new HR people down after over a week of silence just to get the information on rolling over my 401k account. If you want to work for a pure "body shop" who will pretend they don't know who you are after 12 years of working there, this is the place for you. I realize lots of places are probably like this, but ECS used to be so much better.