Pros
Large company with numerous projects will keep you constantly busy but with reasonable timelines owing to good planning in advance. Most people are decent and qualified with very few outliers. Excellent training and reasonable growth opportunities. I did not encounter any of the discriminatory behaviours that have been described in the media lately.
Cons
Size can be a disadvantage when trying to make an impression and move up. There are many others at your position and it is difficult to stand out. It is especially so for Clinical Managers (CM) who have 3 levels to go through (CM; Senior CM; Expert CM) before they can really start moving up. If you want a stable company with decent benefits, that's a great place to be. If you are looking for a quick move up, not so.