Personal and professional experiences . . . CO detectors save lives . . . regardless of which make or model you get. Most -- if not all -- of the CO incidents I've seen here are in places that simply had no CO detectors . . . and a good many of those could have been prevented with some commonsense (i.e. not having a generator running inside a home). Personally, I think one of the most important features in a CO detector is having a battery back-up . . . since a good many of the CO calls I've seen occur in times of power outages when the generators are fired up and ye olde space heaters are dusted off and fired up for the first time in many eons.