Notebookcheck didn't test night-time blood pressure, during sleep. Only day-time? The whole idea of this watch is night-time blood pressure measurement. For anything else you can find better devices.

And tested only with 1 human?

The systolic blood pressure is very inaccurate. This is a 400€ device.

"A Braun ExacFit 5 Connect is used as the reference device for measuring blood pressure. In the average of THREE measurements, the smartwatch deviates by only 0.76 percent for the systolic value and 6.64 PERCENT on average for the diastolic value. The measured values of the Watch D2 are always lower than those of the reference device".

What about skin temperature, it it as accurate as Apple Watch? And other night-time vitals Apple Watch also measures?

The blood pressure readings are roughly 14% higher than comparisons with UK nhs reading and my own omcron monitor, on the sys NHS and my omron sys mmhg averages 130, on HUAWEI D 2 it's 155 average