I’ve had my MX Master for about 4 years now, best mouse I’ve owned. Tracks on almost every surface, easy enough to open and replace the internal battery, and feels great in the hand. The dual friction scroll wheel is amazing for scrolling through large webpages, folders, and lines of code.
Really wish it was at least a bit open source though. It’s capable of so much with the extra built in buttons and additional scroll wheel, but outside of Windows and Mac they are not very programmable