Pros
I started working with Mercury about 6 years ago with another company and they really caught my eye with their drive towards leading the market in embedded/rugged computing. I phased their products into my business and used them to great success with happy customers all around. They approached me and asked if I would come to work for them and I was hoping all the hype was real. I can happily say that after being on staff for a bit, this company is practicing what they preach and the culture is outstanding. Everyone I have interfaced with shares the same values and works together to common goals with little politics. I am lucky to be found and now a part of a group that has made outstanding strategic decisions and is growing very quickly. I wouldn't hesitate to join up if you get the opportunity.
Cons
Not really a con to me.....but Mercury is growing very rapidly so they need a LOT of good people immediately. No place is perfect and the pace at which they are scaling I am sure there will be some turmoil and confusion. This is an exciting time to get to be a part of this turmoil and process of rapid change, but some folks will not be used to it.