Pros
Very (very) flexible, making work/life balance easy Truly fantastic people, especially on the engineering side Whenever someone I care about asks if they should take a job there (as Canonical tends to hire the popular open source kids, whatever their actual abilities to run a business), I tell them, "Yes, if you just want a place to hang out for a year or two and not work very hard. But no if you really care about growing your career and learning something." Embedded in that counsel is this: it's kind of like a club, not a real company, and clubs can be fun.
Cons
Business plan suffers from serious ADHD. Never focus on anything long enough to really test whether it will work. Instead, out of fear of failure, the company invests in everything that looks remotely trendy, and so never really gains traction in anything. Sure, they'll point to the "market share" they have, but that's never on paid adoption, and always on free-riding users. Of course people are going to use Ubuntu for test projects if they don't have to pay. But they use RHEL when they're serious. While peers tend to treat each other well (except at the senior executive level), the top-down management style can be caustic, at best. It's a place you'll want to wear an asbestos suit, when the criticism should mainly be reflective.