Pros
I have worked at Millennium almost 5 years and in my 20+ year career, this is the best place I ever worked (and I have worked for some very good Fortune 500 companies). This is a fast-growing company, breaking new ground in an under-developed vertical that still does almost everything on paper. So if you have a good idea and can articulate the benefits and especially if it improves the client experience, you WILL be heard no matter where you are on the corporate ladder. The investments in Technology are off the charts and I.T. is definitely a place where you can make a difference. I can't speak for every role, but in my opinion, pay is extremely competitive, work-life balance is outstanding, management and even executive level are always accessible, and the culture is solid. I personally have not experienced some of the negative comments posted here.
Cons
Because this whole entire industry is in a transformational period, there have been a few false starts along the way where we drop everything else we are working on to chase some new opportunity that just ultimately dies out. But to me, that is not only par for the course in a hyper-growth environment, but sometimes the fun part too - the chase, not the dies out part :) If you want a 500 page process manual on how to make a pot of coffee, go work somewhere else. If you want to help shape an industry, this is a great place to do so.