I find it comfortable in either position. I have fairly large hands and tend to 'grip' rather than rest.
It's the best mouse i've had TBH!
I've had the microsoft intellimouse 4, both saitek 1600dpi + 3200dpi gaming mice and the razer diamondback, copperhead and deathadder.
The Saitek's weren't for me. The copperhead and diamondback were technically excellent but a little too small. The microsoft was very ergonomic and close to a keeper but it simply was not fast enough for me.
The deathadder offered the size and ergonomics of the intellimouse but added the smoothest and simply best mouse tracking i've ever felt.
But be warned if you're a lefty... it's shaped for right hands only.
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