Pros
ThoughtWorks is a company full of awesome people who are committed to continual improvement of themselves as consultants, technologists and people. There are opportunities to take on interesting and challenging work, working along side amazing team members. As part of the People Organization (think more hands on supportive Coaching and Development folks), and the Associate Consultant program, I feel that TWs provides great support and coaching especially to people who are just entering their careers in software development. It is great to be part of a company that demonstrates they care both about their employees as well as society overall as opposed to a company that only speaks about it.
Cons
As a consultant, the travel can be a challenge and the varied nature of projects and working with clients can lead to more inconsistencies in the type of work you will do.