Tom your decision is based on one detector. Which simply could have been a lemon.
In the last few years there have been changes in detectors and more importantly, new information being pushed out. A cheap
ionization type smoke detector dies in 5-7 years, they do not last forever. Apparently airborne dirt clogs the detector grid at that point. So manufacturers are now offering detectors with a built-in 5-7 year battery, and when it says "Replace" that means toss the whole thing out and replace it, not just the battery. Since they cost about the same thing and you'll only hear the midnight chirp of "feed me!" once every six years or so, that makes sense to me.
You can also get these combined with a CO detector--and since they also die as they age...still makes good sense.
But I've personally seen a number of ionization detectors simply NBOT GO OFF while there was obvious smoke in the room. Some from aging, others because the ionization detectors take about 30 seconds longer than the photocell ones to trigger. If you've ever watched a fire grow, that's critical time. And the photocell detectors don't quietly die in five years like the ionization ones do.
So bottom line? Avoid the $10 detectors, try to find something better ($35-50) and shop around. There's apparently a huge markup and a huge variation in selling prices, and some of the new combined units are being sold for way less than the price
of the old separate ones.
For any of them, I'd "marinize" them by putting some silicone grease on the battery contacts, but I do that for anything with electrical
contacts in salt