I'm the kind of mom who checks a lot--probably more than is good for the baby, and definitely more than is good for me. The breathing charts are like an anti-anxiety IV-drip. Whenever I feel the impulse to check, I tell myself "If there was a problem, there would have been an alarm. Everything is fine." like it's a mantra or something. Then I check anyway, because who doesn't like looking at their baby? But at least it doesn't feel like a compulsion.
PS: I was as skeptical as I was hopeful when we first got it. I trust it pretty well now because the alarm goes off every single time I take her out of the crib because I never think to turn it off first.