Good but it takes water for fun and breaks. Only in sunny weather.
edit I change the rating to 4.
I would give it a 5 but because it is not waterproof, it doesn't light up at night, and it has a difficult menu setting (basically not that difficult but it has a small rubber button that is hard to press) I give it a 4.
It had taken in water as I washed the machine with a hose not with a pressure washer and the dial had filled with moisture while the digits had almost disappeared. I left it for many hours in the sun with the battery removed and it works normally again.
I have had it for almost 2 years.
In terms of measurements, it is very good if you match the wheel to the correct dimensions you have the actual speed.
I have it on a Vstrom that steals 7-8% and indeed at 100 km it shows me 93 km/h at 150/139 etc