My company operates on a freemium model. It's a big hassle, as documented in the section about not doing freemium, but it's also something we decided was fundamental to our main distribution channel which is the Chrome Web Store (breaking another of the rules in the article - but maybe check the last section).

I haven't run a non-freemium SaaS company, but I do see what benefits it would bring if we were able to operate on a typical 14 or 30-day trial model. The big ones that would bring are a much shorter sales pipeline and shorter feedback loop on ad spend.