Pros
GT offers the chance to work for high profile individuals and large global organizations. They also have a strong internship program which trains college graduates for an entry level PR position. If you are truly passionate about public relations and willing to essentially live at work; this might be a good fit for you. They also have a strong compensation package, but it is possible to make the same (or more) money doing a job that's MUCH less stressful.
Cons
There is no work life balance for any employee at this company. Expect to work long hours every day and over the weekends. It's difficult to take time off (even paid time off) and completely disconnect. Daily tasks are always marked as urgent, even though some things could likely be done with a longer deadline. This makes for stressful days and can lead to silly mistakes due to rushing. At the associate level (0-4 years experience), your success will be measured by the number and frequency of media interviews you bring to the table. All other qualities (relationship with the client, account organization, leadership skills) really don't matter at all. The senior leadership team is quick to applaud those who secure high profile media interviews (and give them "awards" during team meetings), but are also quick to completely cut out any person who they decide isn't meeting their needs regardless of the work they are putting into their accounts and regardless of the other skills they might bring to the table. GT is every man (women) for themselves. While they claim to focus less on the number of interviews and more on the quality opportunities which building meaningful relationships with the media, that is not true whatsoever. They often encourage sending pitches (and calling) a large number of reporters even if the topic is not timely, newsworthy, or a match for their beat. Those at the associate level are generally over worked and under-appreciated (although this may be the case for most public relations jobs). They are also seen as expendable/replaceable which could explain the very high turnover rate. Very few are promoted to the senior associate role and even fewer advance beyond that. While the company claims to be open to new ideas or changing the way the PR industry operates, they do very little in reality to achieve that. They put out a press release survey a few years ago about what the media really thinks about press releases, but they continue to pump out dozens of typical "boring" press releases every month anyways. Since the account managers are generally the main contact for clients, the only way to implement real change on an account is for them to ask the client. Generally, they are not even willing to have that conversation or are not willing to push the client to see the benefits of doing something a new way.