The MX Master is a mouse with five buttons for righties. There are the left and right buttons, as usual. Along the left side of the mouse are back and forward buttons that are set by default to be used as the back and forward functions in your browser. The fifth button is located on the thumb cradle, and by default, it’s set as a “gesture button” where you hold the button down and then move the mouse up, down, left, or right to perform the same three-finger gestures you can perform on Apple’s Multi-Touch touchpad. All the button functions can be customized from their defaults using the Logitech Options software, which is accessible through System Preferences after installation.
You’ll also find not one but two scroll wheels. The main scroll wheel between the left and right buttons scrolls windows vertically and also has button functionality that can be customized. The scroll wheels on the side scrolls windows horizontally, and in Safari, can also be used to go back or forward a web page. If you want to change the side scroll wheel's function, to say, control the volume, you can do so in the software.
I never use the back and forward buttons on the MX Master or on the Performance MX; I actually find the placement of these buttons on the MX Master awkward for me to use. I’ve embraced the side scroll wheel, though; I use it to zoom in and out of the screen when I encounter type that’s a bit small for my aging eyes, or I’m editing an image.
Like the Performance MX, the MX Master uses Logitech’s Darkfield Laser Tracking, and I never had any tracking issues while testing on different surfaces, including glass tabletops. The mouse moves very smoothly and effortlessly.
Both mice look very similar, but I felt like the MX Master had a body that’s a bit straighter than the Performance MX. The Performance MX’s curve felt more natural in my hand, but the Master MX felt good and comfortable and never triggered any pain in my wrist or hand. (I don’t suffer from repetitive strain injury, for what it’s worth.) Of course, how a mouse fits is a completely subjective thing and varies from person to person, so if you can spend a few minutes with a mouse before buying, it’s a good idea.
The MX Master feels solid and sturdy, and its 5.1 ounces (with the battery) is just right for me. I prefer heftier mice. A mouse like Apple’s Magic Mouse 2 ($79 on the Apple Store) doesn’t suit my wants and needs.
The Master MX has a built-in, non-replaceable rechargeable battery. Logitech includes a micro USB cable that’s for charging only. I’ve been using the Master MX for several months, and usually I can go a whole work week without needing to charge the battery. (I charge it over the weekend.) I’ve had about a dozen instances towards the end of the week when the battery needed charging. Logitech says it takes 2 hours, 45 minutes to fully charge the battery, and that should last 40 days on six hours of use per day. You can still use the mouse while it’s plugged in.
I prefer the removable AA battery of the Performance MX. It provides more options for charging (I can replace the battery if I don’t feel like being tethered to the charging cable). And I don’t have to worry about the battery’s long-term viability.
One of the nice features of the MX Master is that it gives you two options to connect wirelessly to your Mac. Usually, a mouse connects by Bluetooth or through 2.4GHz radio frequency (RF), which requires a USB receiver to be connected to your Mac. Logitech includes both. I used the MX Master via Bluetooth without a hitch.
If you use other Logitech devices, you may want to use the USB receiver. It’s compatible with other Logitech devices that are equipped with the company’s Unifying technology. You can connect up to six devices to one receiver.
There’s a lot to like about The Logitech Master MX mouse. It has a good number of customizable buttons, it’s solid, and I found it comfortable. If you like your mouse to be light, low-profile, and have a minimal number of buttons, look elsewhere. The fixed battery may cause the Master MX to be a non-starter for some, while the two wireless connection options is an attractive feature. The Performance Mouse MX is still my favorite (it fits my hand a little better), but I’ll use the Master MX without hesitation.