Bests & Worsts Reviews from Amazon

This mouse is much improved from Anker's previous ergonomic mouse Anker 2.4G Wireless Vertical Ergonomic Optical Mouse, 800 / 1200 /1600DPI, 5 Buttons - Black which I gave a direct comparison with Evoluent. I'm a designer who work with computer at least 8 hours a day, mouse is practically an extension of my hand. As result of that, I've developed carpal tunnel syndrome that started with a sore wrist and then tingling sensations in the arm. BTW, the tingling sensation is a sign of injured nerve. If you're feeling that, go see your doctor ASAP. Luckily for me that I caught it early, with combination of exercises, right sitting posture and vertical mouse have saved the wrist. With that said, here is a quick comparison between this mouse and Evoluent VMR4 Brand - Evoluent VS Anker Price - $100 VS $16 Build Quality - Solid (1 years old) VS Feels solid (only had it for one week, time will tell) Size - offers different sizes VS One size fits all, too small for large hand. It fits my hand perfectly (US medium gloves size) Ergonomic observations: 1. ANGLE: Anker mouse is not completely vertical, so I find myself resting the weight of hand on one spot; the pisiform bone against the tabletop surface. No such problem with Evoluent mouse, because of its form where the hand is resting on top of it. 2. FORM: It's MUCH improved from Anker's previous vertical mouse. The hand rests comfortably on the mouse, but part of hand ( from tip of pinky to pisiform ) is dragging on the desktop due to its small size. Evoluent VMR4 has a lip for that part of hand rests on, plus its larger form lets you rest the entire hand on top of it without making contact with the desktop surface. 3. BUTTONS: Even though this version's buttons are better than the previous one, they are still not as easy to click as Logitech and Evoluent.This matters a lot to people who need to click and hold the buttons, doing that requires you to squeeze the mouse which means more stress on the hand. The middle button/scroll wheel is hard to press, Evoluent has a dedicated middle button, that is a must for CAD users. 4. RESOLUTION: I can't tell the difference between 800/1200/1600 DPI in any mouse, partly because I don't install mouse driver unless I have to. When it comes to OS drivers, less is more. This is an excellent mouse for casual use. For extended usage, I would recommend Evoluent's ridiculous priced mouse over this. Vertical mouse takes sometimes to get used to, but it really works and will save you from carpal tunnel. Vertical mouse is just a part of equation, exercises and right sitting posture are the other crucial factors of a healthy body. Lastly ergonomic is different from person to person, sometimes it takes a few tries to find the right device for you. I can't participate review discussion as much as I would like to. But I'm sure others will help out with your questions.