[anfractuosity]

Are you sure about that, I thought ones with Americium were more sensitive? I'm pretty sure you can still get both.

Edit: Seems I'm not right regarding sensitivity, wiki says:

"Ionization detectors are more sensitive to the flaming stage of fires than optical detectors, while optical detectors are more sensitive to fires in the early smouldering stage"

Wow it also says:

"Where an ionizing smoke detector has been the only detector, fires in the early stages have not always been effectively detected."

That's worrying.

[Reason077]

Less sensitivity (or rather, being able to have a higher threshold for sounding the alarm) is actually a good feature for general domestic applications.

You don't really want the thing going off every time someone burns a bit of toast or it just becomes an annoyance, and therefore at risk or being removed or disabled.

[anfractuosity]

Yeah that's true, I guess personally though I'd rather put up with some false positive alarms from toast etc.