Luckily I have no major medical issues yet so Road ID seems liek a , however I just tape my information on my bike with clear tape and on top of my helmet also. I always have my license, phone and a little bit of cash in by shirt pocket. I also enable live tracking on my phone with MMR, especially if I am going somewhere secluded for my ride, so my wife or friends will be able to find me if I am overdue.
I have thought about the RoadID though.