SteerMouse Makes My Logitech Mouse Better
Logitech's "Options" (and newer "Options+") driver software isn't as lovely. Besides its odd issues, such as old versions being incompatible with FileVault, it's a "large" app for something that mainly maps button presses to actions. It has a jarring, non-Mac-like interface, and supports a lot of features I'll never use.
Enter SteerMouse. Let's get the price out of the way: yes, I'm talking about a $20 app to replace the free one that comes with my mouse. It's worth it. SteerMouse only configures the mouse speed, button-to-action mapping things, and other directly mouse-related settings, and it does it well. It's installed as a System Settings pane, looking and feeling almost like it shipped with the computer. Unlike Options, it doesn't like to call home to its maker (thanks, Little Snitch!), and it lets me map the top button to a helpful action (instead of using it to switch between 2 speed settings, which I never once did).
In short, buy it. It's better, lighter, more native, and more private than Logitech's software. Even at $20, I recommend it.