Ever delayed implementing a modern web feature because you weren't sure if your users' browsers would support it? Or kept heavy polyfills around longer than needed? You're not alone. While Baseline gives us clear signals about global browser support, there's been a missing piece: knowing what your users actually support. The RUMvision team solved this by combining Baseline data with their real user monitoring (RUM) data, and the results are very interesting. Teams found they could adopt modern features months earlier than planned, and some discovered they were maintaining polyfills that 97% of their users didn't even need. Others discovered that it was wise to postpone implementing new features because their audience wasn't ready yet.