I've tried both Fitbit and Garmin. I found Garmin to be very inaccurate for things like stairs (we have tons of stairs in our house) and particularly sleep. It would say that I'd slept soundly for 8 hours, which was completely inaccurate. Fitbit (Charge 3) has seemed much more accurate for stairs, steps, and sleep. Though my H finds Garmin is good for running, as it shows certain stats that I don't think Fitbit does. Haven't tried Apple Watch. Which is somewhat surprising, as I sit here typing on my Macbook Pro with my iPhone next to me...