The Milwaukee M18 battery and charger system is praised for its exceptional performance, features, and durability. Users appreciate the smart charging system that intelligently stops charging when necessary and the round-robin charging capability of the large charger. Despite their high cost, many users find value in the system, especially during sales. Reverse engineering insights highlighted the use of an aging microcontroller and ASIC for battery management, leading to discussions on improving existing battery packs using modern batteries like LiFePo4. Comparisons are made to other brands, expressing disappointment in their lack of quality. Overall, interest in the potential for more standardization in battery technologies, especially in the EU, is evident.