Fun fact: you can assign G-Shift to a key on your keyboard (or G13 gamepad) freeing up a spot on your mouse. BUT if you do this with the G502 Hero the
Logitech - G502 HERO Gaming Mouse has 11 programmable buttons, which can customise all your power moves with just one click. 🎈On-the-fly DPI 🎈DPI Shift Button 🎈Onboard Memory 🎈Dual-Mode Hyper-fast Scroll Wheel
Logitech G502 Hero review: Faster, stronger, but it is better? | Rock Paper Shotgun
Amazon.com: Logitech G502 HERO High Performance Wired Gaming Mouse, HERO 25K Sensor, 25,600 DPI, RGB, Adjustable Weights, 11 Programmable Buttons, On-Board Memory, PC / Mac : Everything Else