It's a numbers game. A tabcat used to be £16 to replace the tracker, if you always replace, and they don't lose it that frequently, then it's highly likely that they'll have it in case of emergency. This device is probably more expensive to replace (and unfortunately the tabcat is now £60 to replace, although you do get two trackers for that cost)
It's better that it "malfunction" and fall up by mistake than not falling off when needed.
If it do falls off (by mistake or because the quick release did its intended job), at least you now have a good starting point where to go search for the cat. Assuming it doesn't fall off the very first day, you might also have a good idea or sense of in which area the cats normally goes strolling due to the tracking feature.