Pros
Easy to get hired (most locations now focus on new hires who start as temps for 6 months or a year, which is great if you do not have experience, or they only hire those with a lot of experience in a rival company). The company is very flexible - you get 15 days of PTO from your date of hire and as long as you get your work done ahead of time, you can take them as needed. Also, the company recently changed their dress-code policy from business casual to allow you to wear jeans everyday if you wish (still under the business casual umbrella, though - clients do visit the offices and you should look put together). Also, working from home has not been an issue when I've needed to, but the company still likes you to be in the office on a regular basis.
Cons
Salary is much lower than the industry standard and negotiation of salary or requests for a raise are generally met with a "Nope". If you are a good, smart, hard-working employee, you generally get taken advantage of in terms of having to do a majority of the workload on teams, however, if you speak up about being overworked it's generally remedied pretty quickly. There is a billable hours requirement (which is standard for a majority of corporations), however, it is unattainable. For the lower level employees you are expected to have 1600 hours of BILLABLE time per fiscal year (ie., time the company can bill to a client for work you've done - if you don't have anything to do, you don't get billable hours). If you do the math on that 1600 hour goal, you need to get 6.7 hours of billable work per day MINIMUM, every single day of the week, WITHOUT taking account for holidays or PTO (or slow-periods within the company where your workload may be at a minimum, to no fault of the employee). In a nutshell, it is not an attainable goal for most people. Additionally, your billable hours goal is worth 70% of your yearly assessment and therefore greatly affects your promotion and salary increase possibilities. There is not a clear path of advancement and you are generally oblivious to what other departments do within the company (and therefore, you are not aware of the opportunities they may present to you). Finally, if you move voluntarily while employed for Towers Watson, do NOT expect a Cost of Living Adjustment to your salary.... even if you ask for it. The response will be "we didn't ask for you to move, you're not worth that to us".