Pros
First, pay is generally good and so are the HC benefits (health premiums are low and they provide you with funding for your HSA). You also get paid a bonus for working holidays and can reach big annual bonuses if you are client-facing. Hours can be long but are generally reasonable compared to other employers. You won't work 11 hours a day but you may need to be on-call for that length of time. The company will invest in you and has made tremendous progress over the last year and a half. During my time at GLG there were numerous re-orgs, reshuffles, and a lot of turnover. Early on, it was long hours on a daily basis, a lack of resources, and the frustration of following "client knows best" at all times. However, a lot of things improved when our budget for headcount was increased. Basically, the company took a lot of pressure off employees by letting them work fewer hours. I do want to call out the culture at GLG. It is very empowering and there is a good deal of transparency at the middle management (and even upper management) levels. There is very much a "we're in this together" attitude that makes working at GLG tolerable - and even enjoyable - despite work that can seem (and is acknowledged by many to be) quite mindless. GLG also made HUGE strides in recruiting a more diverse workforce in a short period of time (and not just ethnicity but people from public instead of private universities).
Cons
The downsides are nearly immediately apparent: with the exception of some very specific roles, you don't have a say in a lot of the work you do. You are expected to follow management's and your client's lead all the time. We went by the maxim: "the client is always right." Despite graduate work in survey methodology and having run a survey research office, no one turned to me or consulted me for that advice - and I offered it all of the time. . It's just not empowering when your expertise is not valued and you don't have a chance to showcase it in front of senior leadership. Also, leadership could improve (C-suite is pretty good but those just below don't seem to make an impact for what they are paid). For instance, the research side of the business doesn't have any clout and so the organization doesn't get much of an industry reputation in that regard. This has to improve or GLG will lose business in its survey and other research offerings. You cannot just count on hedge funds and PSF firms paying your bills if you want to grow.