Pros
If you are joining as a Client Servicing exec, this could be a good place to pick things up. However how much you can learn is really dependent on the team you join: you could join a team with many quick turnover studies and be able to try your hand at analysis often, or you could join a team which has a few major studies and spend most of your time on operational or project management work.
Cons
Lower levels of CS is mainly coordination and operational/project management work. So be prepared for that. Promotion depends alot on visibility of your portfolio. If you have many high profile work that the higher ups see, there is a higher chance of promotion than if you are very good at your job on a bunch of lower profile work. Some of the managers are very good at talking, but not so much at teaching or guiding. Thus how fast you learn also depends on whether you have a good manager. Working hours can be quite bad and you may need to OT alot (at times past midnight). Higher management seems to think this is expected.