Alternative Refrigerants

I've been following the discussions around alternative refrigerants lately, especially with all the new regulations coming out. I'm really curious about the safety aspects of some of these newer options. Specifically, are the flammability concerns with some of the hydrocarbon refrigerants being adequately addressed in residential systems? And beyond that, how do their efficiency ratings truly compare to the older HFCs in real-world scenarios, not just lab tests? It feels like there's a lot of information floating around, and I'm trying to get a clearer picture before my next HVAC upgrade. What's everyone's take on the practical implications for homeowners regarding installation and maintenance?