The MX Ergo S is the best trackball Logitech makes, and the right mouse for desk workers whose wrists hurt from moving a mouse all day. The tilt, the precision button and the months-long battery are genuinely useful. It is not for small hands, not for gaming, and the first two weeks feel strange. Check the current price on Amazon before buying: if the trackball idea clicks for you, this is a multi-year desk fixture.
— THE VERDICT · JUDGEANY EDITORSWhat the MX Ergo S is
The MX Ergo S is Logitech's flagship thumb trackball, the S revision of the MX Ergo, and the changes are the ones that mattered: USB-C instead of micro USB, and quieter main clicks. Everything else is the same idea, executed well. A 34mm ball under your thumb moves the cursor while your hand stays put, a metal plate tilts the whole mouse to 0 or 20 degrees, and a precision button drops the DPI for fine work. At 164 g without the plate and 259 g with it, this is a desk anchor, not a travel mouse. That weight is a feature: it does not slide around while you roll the ball.
Ergonomics: the reason to buy it
Engadget, which picked the MX Ergo S as its ergonomic mouse recommendation, notes the magnetic plate lets you switch between a flatter position and a 20-degree angle, and calls cursor movement exact, with the precision button easiest to operate with the thumb while the forefinger handles pixel-level control. The same review's author is on a second MX Ergo after six years with the first, which says more about longevity than any spec sheet. The counterweight to all this praise is fit. Digital Camera World warns that small hands struggle with button placement and getting the thumb comfortable on the ball, and there is no left-handed version at all. If your hands are small, try before you buy.
Buttons, wheel and software
There are eight buttons in total, programmable through Logi Options+ with per-app profiles, plus a tilting scroll wheel with middle click and horizontal scroll. Digital Camera World found the trackball itself smooth, responsive and accurate, and liked that the ball pops out for cleaning, but found the secondary buttons awkwardly placed and noted that only the left and right clicks got the quiet treatment. Engadget adds that the scroll wheel lacks the quick-scroll of the MX Master line and that the top programmable button is easy to bump accidentally. The 512-2048 DPI range is modest by gaming-mouse standards and entirely adequate for office and creative work, which is what this mouse is for.
Battery and connectivity
Logitech rates battery life at up to 120 days per charge, and reviewers describe it in the same terms: months, not weeks. Charging is USB-C, and unlike the old micro-USB model, you can keep using the mouse while it charges. Connectivity is Logi Bolt or Bluetooth Low Energy, with Easy-Switch between two devices, and Engadget reports switching takes only a few moments. One practical annoyance: the USB-C cable is not in the box, so if you do not already own one, add it to the order. Check the current price on Amazon before buying, since Logitech's MX line is discounted often.