It is a 5 star watch, are there complaints... Sure. It's a bit large, heavy, and the bezel doesn't rotate, and the strap I chose is not comfortable. But... It has relatively great battery life compared with similar smart watches (doesn't match the Garmen battery life) but will last at least a couple days.
Charging speed is OK, wish it was faster.
Performance and functionality is awesome. There have been zero blips in the performance. The screen is bright and very easy to see and read. Speaker is nice and loud for the size.