Has anyone transitioned to an unlimited PTO policy, and how did that affect your company culture and productivity?

Has anyone transitioned to an unlimited PTO policy, and how did that affect your company culture and productivity?

We’ve been using a points-based system for PTO, but I’m starting to see complaints from employees that it feels too rigid. I'm trying to rethink all policies before the new year, so if a different system would work better we can implement it starting in January.