The MX Master has been the default recommendation for a productivity mouse since 2015, and every generation has carried the same complaint: Bluetooth connections drop, stutter, or take several seconds to wake, particularly on Windows machines with crowded 2.4 gigahertz environments. The MX Master 5S, announced Tuesday at $119, moves to a Bluetooth 6.0 radio with channel sounding and adds a redesigned Bolt receiver. Across three weeks on four machines, including one office with roughly forty wireless devices in a twenty square meter area, I recorded zero dropouts and no wake delays longer than about 200 milliseconds. That alone justifies the generation.
What was wrong before
The MX Master 3S and its predecessors used Bluetooth Low Energy with a connection interval that Logitech tuned toward battery life. In a clean radio environment that worked. In a dense one, packet loss produced the stuttering cursor motion that filled Logitech's support forums for a decade. The proprietary Bolt receiver was more reliable and required a USB port that laptop users increasingly did not want to spend.
The 5S changes the negotiation strategy: it starts at a short connection interval and lengthens it only when the link is clean, monitoring packet error rate continuously and shortening again on degradation. Battery life drops as a result, from Logitech's claimed 70 days to a claimed 52, and I measured about 44 days of heavy use in a noisy environment. That is a trade almost everyone will take.
The scroll wheel
MagSpeed, the electromagnetic wheel that switches between ratcheted and free-spinning modes, has been the MX Master's signature feature. The 5S adds programmable haptic feedback, so the wheel can produce a detent at meaningful positions in an application: cell boundaries in a spreadsheet, keyframes in a video editor, or section headings in a long document. Logitech ships profiles for Excel, Premiere, Figma, and a handful of others, and exposes an API.
It sounds gimmicky and it is not. Scrolling a spreadsheet with a detent per row makes precise navigation possible without looking, and scrubbing a video timeline with keyframe detents is the first time a mouse wheel has felt appropriate for that task. Application support is the limitation. Outside the supported profiles the wheel behaves conventionally, and the API has been available to developers for only a few weeks.
The story is rarely the launch. It is what breaks, what ships, and who owns the mess at 2 a.m.
Ergonomics and build
The shape is nearly unchanged, which is correct, because it fits medium and large hands well and has for a decade. Weight is 138 grams, four grams lighter. The thumb wheel and the gesture button remain. Logitech switched to optical switches for the main buttons, rated at 50 million clicks against the previous 10 million mechanical, which addresses the double-click failure that afflicted the MX Master 3 after two or three years of use.
That switch change matters more than it sounds. The MX Master 3's double-click problem generated an enormous volume of complaints and a class action in the United States that Logitech settled in 2024. Moving to optical switches removes the mechanism entirely. It also changes the click feel slightly, with a shorter travel and a crisper action that some long-time users will need a week to adjust to.
Software
Logi Options+ remains a heavy application for configuring a mouse, consuming about 180 megabytes of memory and running a background service. It works, the per-application profiles are genuinely useful, and it wants an account for cloud sync that you can decline. The Linux situation improved with an official flatpak released in June that supports configuration, though not firmware updates.
The one persistent annoyance is that some settings live in the operating system and some in Options+, and the two disagree about pointer acceleration in a way that has confused users for years. Logitech has not fixed this and shows no sign of doing so. Setting acceleration off in both places and adjusting sensitivity on the device is the workaround everyone eventually finds.
Worth upgrading
If you have an MX Master 3S and it works reliably on your setup, the case is weak: better switches and a haptic wheel with limited application support. If you have been fighting connection problems, this fixes them, and that is worth $119 to anyone whose work involves a cursor.
The competition has narrowed rather than expanded. Razer's Pro Click V2 is comparable and worse on software. Keychron and a handful of enthusiast brands make excellent mice with worse ergonomics for long sessions. Apple's Magic Mouse remains a design object that is bad to use. For a mouse you will hold eight hours a day, this is still the one.
One note for people who have been burned before. Logitech's warranty handling on the double-click failures was inconsistent, with some customers replaced promptly and others directed to a support loop that went nowhere until the class action settled. The company now offers a two year warranty in most regions and three in the European Union, where consumer law requires it. Registering the device at purchase makes a claim considerably easier, which is tedious advice and specifically useful for a product with a documented history of a mechanical failure that appeared around year two.
Skarvonix will keep following this beat with reporting grounded in how systems behave outside the launch keynote.
