This is my first heart rate monitor and I am completely satisfied with it. The only negative point I can think of is that the menu is not intuitive, but it is easy to learn, because Beurer provided excellent diagrams showing the available options. I am satisfied with the quality of the product descriptions as well. I recommend reading the instructions first before trying to push the buttons randomly. Apart from this the device is superb.
It finds signal very quickly for me and does not lose it during the workout, despite the fact that I usually run near overhead wires and having a mobile phone close to the monitor. It displays the most important information during a workout: time, heart rate and whether you are in the target zones or not.
The sensor's range is 70 cm which is ideal, because it is less likely to interfere with other devices when not running alone. The contrast of the display is excellent, perfectly readable even in direct sunlight, and the backlight is very bright, too. I especially like the design of the watch strap. The heart rate monitor's strap is a good one, as well.
Maintenance is not a problem, you can replace the battery by yourself in the monitor and you can have the battery replaced in the watch in every small shop offering this service (both batteries are the common CR2032). All parts can be cleaned with soapy water.
All in all this is a simple device, but it does exactly what it says on the tin - it is a 5 star product.