One thing I have learned is that I never pay attention to my ceilings. I recently had a water leak in my living room and the insurance company sent someone out to cut the wet drywall out. It took almost 2 month before they came to patch the 4' X 4' hole. After about the second week I forgot the hole was even there.
In my basement I put 4 in ceiling speakers in for my theater. I never notice the speakers are there and the whole I cut to assist in pulling my wires I don't notice either. I simply covered that hole up with a blank round wall plate.
My point is that you will probably never notice your smoke alarms unless they are going off. So save your self the money that you will spend on recessed smokes and spend it on a quality Smoke/CO2 detector.