I personally don't have a medical alert band as I don't like things on my wrist however I have a badge on my sunflower lanyard which says "Autistic and Proud" so I'm pretty certain that people are aware.
Yes and an epilepsy one. Both have been useful for me in emergencies and paramedics and people around at those times were supportive and understanding towards me. One woman actually said turn off the sirens loud sounds upset her and she got that from Google on her phone just because the band said "this person has autism".
