This is what helps me to switch gear the fastest. If your doing just a simple 2 item switch, you can actually right click the item towards the bottom and press the "+" key instead of 5, and because it double clicks, it clicks the highlighted item, aswell as the one directly under it.
I think I might actually try this because I had never even thought of the difference between a wired and wireless mouse. My current mouse is wireless and I love it, but I have definitely noticed a delay in clicks sometimes. I will click the item, but the response time is slow and I often have to reclick things because it didn't register the first time. It can be a nightmare if your trying to switch fast in PvP.