Amazon.sg:Customer reviews: Logitech MX Vertical Wireless Mouse – Advanced Ergonomic Design Reduces Muscle Strain, Control and Move Content Between 3 Windows and Apple Computers (Bluetooth or USB), Rechargeable, Graphite
To calculate the overall star rating and percentage breakdown by star, we do not use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
I'm relatively big (190cm/6'3") and have been hunting for a mouse design for decades that relieves my hand and arm fatigue. This mouse seems to have finally done it for me. I've tried many other mice including the Microsoft sculpt which are good, but not as good as the Logi MX Vertical for me. My use fatigue was to the extent that for many years, I had to use a mouse in one hand for half a day and in another for the other half to give each hand a break. I don't need to do that yet with the Logi MX Vertical - at least so far after several months of use.