Pros
Lam has great people who share a vision of a successful company. There are lots of "old-timers" here, which is a good thing - that means that the company fosters happy employees who are invested in the company. It doesn't mean there aren't new blood roaming around, because they are everywhere, as well. Lam has a better, calmer environment that its main competitor AMAT, IMO, speaking from my direct experience at both places. The compensation at Lam is good and the lateral/upward mobility is wide open. The ceiling goes very high for both individual contributors and people managers, all you need to do is ask for it.
Cons
I read some of the previous reviews, and my take on it was, each person's experience is their own. Their reviews are probably weighted based on their interactions with their direct manager and their close coworkers. As a crusty old engineer, I know that nothing is permanent and no situation is final. A bad manager will soon be replaced with a different one, and work roles change as well. Look at the bigger picture. OK, so what's bad about Lam? Well, some of the buildings on the Fremont campus are showing their age (I'm looking at you, CA01), break areas are nothing fancy, and parking can be spotty at times. Yes, the work load can be incredible, but what did you expect for a Silicon Valley tech job?