They are all garbage, without monitoring brainwaves you have essentially zero useful information about sleep quality/duration/stages. No amount of accelerometer/heart rate data is going to accurately reflect your sleep stages, regardless of what marketing spiel you read.

For a brief time there was a consumer product "Zeo sleep monitor" which was a legitimate EEG-style brainwave headband you would wear to sleep. From what I recall, comparing it's results to those of in-lab sleep studies, it was fairly accurate.

Sadly they went out of business as it was a fairly niche product and pretty expensive.