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- Verified Buyer
I started using this mouse not because of carpal tunnel syndrome, but chronic tennis elbow. My doctor first suggested a wrist brace to try to limit the effects of work (programming) on elbow pain, but that got old in a hurry, so I decided to try a vertical mouse and adjustable keyboard.Positives:It feels quite natural, and takes little time to get used to. The hand position is rotated some 60-70 degrees from horizontal, and this should help with RSI concerns.There is a middle mouse button! I haven't had one of those for ages, but it's great, especially in Linux where "button 3" is the preferred way to do a quick text paste between windows. For most mice, the scroll wheel doubles as the middle button, but it can be difficult to press a wheel without turning it at the same time. This is much easier for me.Sensitivity is adjustable on the mouse itself, in four steps (high, medium, low, extra low). I find that either of the middle settings works okay for me; high is out of control, and extra low makes it hard to get across the screen. So the range of adjustment seems pretty reasonable. I can conceive of situations where I might want to change sensitivity temporarily - say, when doing fine detailed graphics work. This mouse will let you do the adjustment without messing around in the operating system's control panel.Negatives:The mouse body is lightweight plastic, and on a smooth surface the thing moves too easily. Why do I care? Isn't easy movement a good thing? Well, not necessarily. It matters in this case because the buttons are actuated horizontally. I cannot click a button without jiggling the pointer. A mouse pad of the right texture might help here, but what the manufacturer really needs to do is put some inert mass into the mouse body. Or, they should provide a compartment to let the end user add weight "to taste" without having to take the mouse apart and void the warranty. The wireless version of this mouse probably avoids the problem by virtue of containing batteries; keep that in mind when making your choice between them.**LATE EDIT REGARDING MOUSE WEIGHT** More than a year later, with the product well out of warranty, I finally looked into this issue. The bottom plate of the mouse can be detached via 4 screws: two are under the middle product label (feel around for subtle indentations, and stick a small phillips screwdriver through the paper) and the other two are under the front-edge slider pad, which is easily peeled away to expose them. Once the bottom is removed, you can see how much central space you have to work with. My solution was to take a handful of metal hardware (mostly computer case screws, but anything will do if the pieces aren't too big), put them in a plastic bag to prevent disturbing any electrical connections, tucking them into the mouse body, and then reattaching the base. It makes a night and day difference. The added mass makes all movements more positive, less squirrelly. I'm not using a pad, but putting it directly on a hard desktop surface. Because this works so well and is such a simple modification, I'm increasing my review rating to 5 stars. This is now an *excellent* mouse!A tip just for Linux users:Firefox, at least, expects any extra "back/forward" navigation buttons to be reported as numbers 8 and 9. On this mouse they are unconventionally numbered 8 and 10, 9 being reserved for the mouse wheel (scroll-up=4, scroll-down=5, wheel-press=9). Depending on what desktop environment you run, you might have a graphical control for button assignment, but the following command, as part of my X session startup script, fixes it for me by swapping 9 with 10: xinput set-button-map "Kingsis Peripherals Evoluent VerticalMouse 4" 1 2 3 4 5 6 7 8 10 9 11 12 13 14
