Update after a long ride on Oct 14.
Komoot navigation. Don't expect too much. It is not Google Maps navigation. Komoot's guidance doesn't show the road closure, and traffic condition. Also Komoot's guidance is sometimes confusing.
Battery life. I started my 100km ride with 90% battery remaining, and after 110km with 5 hours total, it showed 70% remaining.
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This is a great bike computer for those who don't need to upload the exercise record from this device.

I use a Polar running watch to keep tracking my exercise and activity. The Polar system automatically submits the exercise data when I connect my watch to my iPhone. Basically I don't need the same function on my bike computer. What I need is a big data screen with current speed, average speed, cadence, HR, active time, and distance. Navigation is a great bonus. The Polar watch is great, however, it only shows 4 data on one small screen. This device does show many that help me to know how I am cycling.

Here are some pros and cons to this computer.
Pros -
Price. Not many other devices can beat this.
Komoot navigation. Works great. Since you are on a bike, you don't need a precise map for navigation. Turn by turn guidance is enough.
Product design. In accordance with Meilan, this device was designed by a German design team. Looks solid, sleek, and cool.
LCD panel. Fine resolution and easy to see. A Japanese part?
Positioning. Captures satellites fast. Meilan says this device captures American GPS and European Galileo. I tested and uploaded a file to Strava, and the tracking accuracy was about within a 5 to 10 yard range in a rainy and overcast condition. Not too bad.
Dualband. My HR sensor does dual, too. Bluetooth for my Polar watch and ANT+ for this device.

Cons -
Printed manual in the box. Too small and impossible to read. You need to download it from Meilan website.
Instruction about connecting sensors. The device does connect ANT+ and Bluetooth. However, the device only displays "Bluetooth," even the device captures the ANT+ signal. Need improvement.
Languages. Some youtube video shows it has many languages available, but in reality, English, Polish, and Spanish.
Setting-up. A little cumbersome. Especially once Bluetooth connection for Komoot is lost, you need to connect it from your phone again. Once the setup is done, it is very easy to use.
Inability to wirelessly upload the exercise file from the device. This might be the biggest con for some users.
Meilan phone app. Can't understand what it does.

My conclusion is that this is a no joke bike computer. Once the setup is done, it is easy to use. Good positioning accuracy, turn-by-turn navigation with unbeatable price. If you are using Garmin or Polar running watch and don't want to spend a fortune on a bike computer, this is for you.

It's easy for start using. Work with training peaks app. And have a good price.

Gave to my son who likes to take long rides. Said it does what he expected. As he is the expert, I cannot give any technical info except to say that he likes it and uses it whenever he heads out with his bike so it must be good.

Easy installation, all the data seems to be accurate. Come with Komoot license which is a huge plus. Surprisingly light weight. You don't need to pay more for trail maps or subscriptions. Great for some casual MTB and exploring new trails. Menu can be improved but once you get used to it, not a big deal. Save a hundred bucks from Garmin and invest in other gears.

Works well, good quality and easy to set up.