This might be an interesting discussion, but have you ever been out of the country and have noticed how the alarms are different in places like the UK? I remember when I visited England and Scotland in the summer between my fifth and sixth grade year when I noticed how odd sounder-strobes and call points looked! I didn’t know how to activate them, since they didn’t have any text instructions, and the sounders did not have any sort of FIRE lettering on them. Strobes (I don’t think) are a requirement there either. I have seen a few videos featuring sounder-strobes, and some of them appear to be LED-based rather than xenon-based.
Of course, Andrew’s detectors that he uses in his house are Apollo models, but does anyone know of any smoke detectors that American systems use that were originally UK models?