The Rival 500 isn't a great mouse, but its innovative thumb layout and the inclusion of haptic feedback are interesting glimpses of the future.
Intuitive and useful thumb-button layout; Beloved PWM3360 sensor; "Tactile Feedback" is like controller rumble in a mouse
"Tactile Feedback" is only in a handful of games; Short; squat; and heavy; Tons of buttons; but none feel great to press