It could have been 5 stars but the battery life is honestly terrible. My previous mouse was a Razer wireless mouse and lasted about 3 or 4 weeks on a single rechargeable AA battery before needing to be recharged. And it weighs a little more than the Glorious Model O. It's a better mouse overall, but I definitely miss the long battery life and I don't see any logical reason why they can't put a bigger battery in the Model O. Weight, to be honest, not that important. Otherwise, the buttons are nice and clicky, the scroll wheel is very tactile, and the software lets you set your own custom dpi profiles.