Pros
I joined to cut my consulting teeth but Customer Systems delivered much more. Few get the opportunity early in their career to work with such a professional firm, in roles with substantial responsibility and with a client list that is second to none. The opportunity at Customer Systems easily out paces that offered by the big consulting companies and I saw the intake, year after year, progress fast and successfully. The company has absolute integrity and this is at the core of its success. It tells its customers that it is the best at what it does. It is. It tells its customers it will solve their problems at a fraction of the cost and faster than the big consultancies. It does. The standards and values of the company have delivered it great success and they have done the same for me and for my career. In addition to providing great consulting careers Customer Systems is a unique place for those wanting to go further than this. It has a strict policy of promoting from within and during the ten years that I worked at Customer Systems I did not see this policy broken even once. Many of my peers progressed to be Managing Consultants, Consultancy Managers and Divisional Managers. The latter of these two roles carried a level of P&L responsibility that I have seen no other company entrust so early and so willingly to its people. Customer Systems was a key step on my path to becoming Country Manager of a software services business and then Managing Director of a consulting company. People that I worked with at Customer Systems have progressed similarly and amongst these I see another MD, senior execs at software companies and at all of the main consulting firms, senior managers at many large international corporates and also the senior management team and consulting team at Customer Systems. If you are considering joining then expect to work hard, progress fast and achieve plenty. If you've ambition Customer Systems will match it. If you're looking for something more routine then you have a wide range of employers to consider all of whom will offer you something more mundane. Take your pick.
Cons
Provided that you have your eyes wide open there is little to complain about. There are some negative reviews on here and my guess is that these are from those who were kidding themselves about what is involved in carving out a career. Take with a pinch of salt the views of a consultant who is surprised at a dress code which is simply to wear a smart business suit, white shirt and tie.