Pros
I worked full time at MMs for 2 years and grew my knowledge of software, SaaS, and sales immensely. It was a major stepping stone in my career and I was still learning constantly when I reluctantly left for an opportunity abroad. It's a small company with a tight-knit management team who have a lot of competing priorities, so you sometimes have to fight for their time, but when push came to shove they were always ready to focus and help any employee that asks. The product is great and provides a major wow factor to the customers, which for me is a major plus. I would never want to sell a product that wasn't impressive and delivering ROI. The development team are super easy to engage with and they constantly innovate the product. It's a great place to work.
Cons
It's a small team and you have to be a self-starter to make the most of your opportunities there, but if you are up for that then you have a lot of leeway to create your own role and try to achieve something meaningful.