Just a few thoughts ...
I picked up a Logitec G500 Gaming Mouse last November and immediately started hitting the center line a lot more. It doesn't slow down the meter ... but the response time between me hitting the mouse button and the reaction on the meter is almost immediate. I figured it was either the mouse --- or that specific day I got a lot better. (I'm leaning towards the mouse)
As a note --- In March I met a few buddies I play with down in Virginia for some golf and WGT. One of them is one of the better players on the site. I brought my computer set up .. and he signed on to play a game with it --- and couldn't handle the quick response time on the mouse. He was early on every hit ... which tells me the mouse response time really impacted his game.
There are lots of gaming mice out there .. i have no clue which is best or if it will even make a difference for you .. but it did for me.
Oh and whatever you do .. stay wired.