This Gigabyte mouse is pretty sweet!
The mouse feels sturdy, all the button have a good positive clicking action but are easy to press, and the scroll wheel has a great detent (click) but still scrolls smoothly and feels well built. The scroll wheel also has a rubber strip round it (much like a tyre) so feels very nice under the finger.
It takes two AAA batteries, so has just enough weight to it without feeling too light or too heavy.
It's about halfway in size between your usual portable mouse and a proper desktop mouse. If you have small to medium hands you'll probably be ok using it for extended periods, but if you have large hands it will be too small unless you adopt the 'crab' grip method!
My only gripe is the software - I downloaded the latest version from the Gigbyte website, as I would have like to set the left and right tilt action on the scroll wheel to something other than horizontal scrolling, but there is no option to change that.
However, all in all, a great mouse for less than 20 quid, which easily punches above it's weight. You could pay another 30 quid or so for a Logitech mouse, but you'll be pretty happy with this one (and have enough money spare to buy yourself a treat).
p.s. Play, sort out your review panel, why can't I enter the 'pound' sign?? Very strange!