Pros
MxL is not afraid to take big risks -- in technical decisions and in people. I've gotten the opportunity to do things here I was not able to get elsewhere. Smart decision-making, technical mentorship, and humility are valued as much as technical virtuousity. Barriers between teams -- analog IC, digital IC, systems -- are low. Opportunities to learn are plentiful for those who seek them out. As a new grad, you will quickly get the opportunity to work on circuits that will end up in successful products.
Cons
This is not the easiest gig in town. Like being part of any team with high performance and high standards, you'll be surrounded with people who want to succeed and make great products. It is not always easy. However, as the company has grown, there is much more modulation -- downtime after tapeouts, "normal time" between projects, opportunities for technology development. Even during the difficult times, I've gotten support from my managers and peers to take care of personal needs and family issues when they come up.