Pros
Moz takes great care of its people, with fair salaries and fantastic perks. The office environment is great, and the culture that's been built is extremely strong. Most of my coworkers were great people that I'd happily be friends with outside of work. This could be seen as a pro or a con, depending on what you're looking for out of work, but there's basically no consequences for failure or mistakes, and Moz (accurately) has a reputation as a place you come to "coast".
Cons
For a company that's been around for 15 years, it still feels really startup-y at times, in concerning ways. For example, they still know next to nothing about who is using their product or in what ways, yet they're making business decisions about tackling certain market segments without even understanding said segments at an actionable level. The company is customer-friendly to a point that is actually detrimental - decisions to do things like adjust pricing or sunset rarely-used products are met with extreme internal resistance for fear of upsetting a handful of customers. Engineering teams are matrixed/interdependent in a way that I've never seen at any other software organization, which makes accomplishing even the smallest task necessitate tons of meetings, prioritization decisions, and horse-trading. Too many mid-level managers control fiefdoms in ways that makes it easy for them to foot-drag on anything they're not interested in doing. During my tenure, we spent a lot of time talking about how we were trying to do too many things - and yet we never decided to do less. Overall, a company with a lot of individual talent that unfortunately doesn't add up to much when paired with unclear strategic direction and "legacy" employees that aren't interested in operating in a more effective way.