Pros
Through my time at Red-Hat I worked in more than one site. The transition betwen the sites was quite smooth. The folks are very professional, you can learn a lot, even as experienced sofrware engineer. You can get expoesed to latest trends and technologies, aspecially in upstream (open source) version of the projects, depends which project of course.
Cons
I think the salary reviews should be formalized, they are not tightly coupled with the employee assessment process, so in some sense it gives us employee less motivation to invest in these assessment processes. For senior engineers who are already "deep in the system" it may be a bit hard to switch in the project to do something else (but there are examples when people actually did that) - sometimes it's a matter of the engineer taking an intiative , invest extra time, and perform the shift after showing results - but I think management should encourage this more. Red-Hat is also an amazing place ify ou're a remotee and don't have a thriving IT industry near you - we have excellent engineers in places like little vilages in their home countries, and countries where the IT industry is not thriving.