Pros
sometimes it was just really hard to find time to grow because of other responsibilities. it's 100% on you to drive this with your future manager(s). if you're a junior guy, expect a challenge in working your way up the ranks. and be prepared to play the game. it's simply not enough to just "work hard." in other words, you get the benefit of working with some of the smartest people in the industry. you also need to stand out against those same people in order to get promoted. it's competitive.
Cons
they push a lot of automation (they have to). their change process is onerous. there are re-orgs every year to 18 months. but you also get to interact with network designs/topologies/technologies that exist no where else in the world. you're designing for unheard-of scale. there's just something really cool about that.