Pros

Excellent people - in my time with the company I only found 1 person that I didn't really enjoy working with. Most are very competent.
Reasonable chance to progress, but work/life balance has to be put to one side if you want to be promoted beyond PC grade.
Good level of trust from senior managers - your opinion and experience counts and isn't just ignored when it conflicts with some political agenda with a client.

Cons

Work/life balance is typical of consulting firms I think. Long hours when on client projects.
High expectation of your commitment to non-client work, even when client work is 70hrs a week. I found a constant barrage of requests for me to spend time on proposals/bids, sometimes requiring even more hours than client work.
HR function is OK on the surface and the firm was generous when I had a period of long-term sick leave. However, when there are cutbacks, you're out.

Advice to Senior Management

Invest some of the money that you have sitting around (you know what I mean). Internal IT needs a rethink and continued investment in new sectors would help.