Really? I didn't notice much difference going from the battery one to the chargeable one outside of the obvious need to plug it in when not using it because it's unusable plugged in.
The main difference is that every supermarket and convenience store sells replacement batteries for the original, but when the battery in the Magic Mouse 2 is something you need an iFixit guide and a specialist retailer (and the knowledge of how to avoid chinesium fakes) to replace when it inevitably goes all puffy and fire-hazard-y.