Pros: Price
Cons: Frequent slowdowns, weak WiFi reception, very short battery life.
Overall Review: You get what you pay for. If you have a strong WiFi signal, never unplug the laptop and don't mind frequent UI lag in Windows (I tested 2 laptops, both have the same issues), get this to save money. Otherwise, get something that works.
Pros: - comfortable fit in my right hand - natural hand position - hand does not have to twist as is the case with standard mice - mouse surface is not rough to the touch like some other mice - the wheel is quiet, scrolls quickly yet precisely
Cons: - the dedicated "Windows start menu" button is pretty useless - the back button is kind of hard to press as it requires a lateral thumb move - not comfortable, but at least you won't press it by accident
Overall Review: Have been using this mouse for years and it still the best one for me.