G303 heavily depends on your form of grip and if you like it's shape and sensor. G303 is a claw and fingertip grip, more favoring to those of fingertip than claw. Taken into consideration it's size dimensions are Height: 115 mm (4.53 in), Width: 65 mm (2.56 in), Depth: 37 mm (1.46 in), Weight: 127 g, mouse plus cable (4.48 oz), Weight: 87 grams, mouse only (3.07 oz), so it's an overall light mouse and for small hands.
The sensor is a currently proprietary PixArt PMW3366, which has been known (and even tested by myself) to be extremely responsive with fast swipes and even low/high sensitivity swipes do not cause the mouse to malfunction and can have Logitech Profiles saved onto it's onboard memory.
The build quality is good and...