Purchased and using it for last 1 month. Though light weight and long battery life, it did not serve the purpose of purchase. I find heart rate monitor highly unreliable. When my heart rate on palpation is to the tune of 140-150/min ,the monitor shows any thing from 70-130/min. I think such a discrepancy will also hinder calculation of exact calories burned. Can't comment on step count... I use rowing machine for aerobics. I assume the monitor is not programmed for rowing so grossly underestimate the steps and calories burned. Regarding sleep monitoring..it looks interesting but can't comment on it's reliability as I am sleeping. For me it didn't serve the purpose.