I'm left-handed. Yet when it comes to computers, like most other lefties I know, I use a mouse with my right hand. It's just...how I was taught. So I've never seen the need for a mouse that tries to somehow accommodate both normal humans and sinister mutants. I mean, let's look at the situation here. People buying a proper gaming mouse expect something of a certain quality, a certain comfort. How it feels in your hand is important.
It's why the best mice - I'm talking stuff like the Razer DeathAdder and Naos 8200 - are so serious about their ergonomics. How could a mouse half-assing between hands possibly offer the same level of comfort? And why would you bother, when mice like the DeathAdder ship with dedicated left-handed variants?
No idea. But hey, this category of the market exists because people want that flexibility anyway, so if you really must sit on the fence, the Avior 8200 is a good way to do it. Made by Mionix - they of the Naos 8200 fame, my favorite gaming mouse of them all - it's of course lacking in the bulk or custom ergonomics you'll find in a right-handed mouse. Everything else I like about the Naos 8200, though, is here. It's just a bit smaller.