The Spawn comes in what Cooler Master calls a "claw" shape, claiming a natural grip. Despite the width of the Spawn, we found this to be more or less true, although the surface of the mouse caused our palm to slip a little too easily. The mouse also rocked to the left and right when in use, a disconcerting instability that was distracting during Windows use.
It's also incredibly light, and has very smooth feet — a good thing for dexterity, but a pain when your hand isn't actually on the mouse. We found that if the cable tugged on the mouse in any way, it all too happily drifted in that direction, rather than staying put.
Below the scroll wheel are DPI switchers, while on the right there are two thumb buttons. The latter are easily reachable and distinguished, and the former can be a bit of a pain, as with all switchers found under the scroll.
Cooler Master curiously includes three firmware updates for the Spawn, all for different surfaces. We found that on our Vespula mouse mat and test-bench surface, only the 0.30a firmware worked — 0.31 and 0.32 didn't respond at all, only working when the mouse was placed on our jeans. Despite Coolermaster's recommendation to install the 0.32 firmware, we'd say stick with 0.30a.