In classic insurgency, there was a binding option in controls under the inventory tab called "Toggle Primary/Secondary". Binding a key to this allowed you to switch between your primary and secondary weapon with a single toggle key, instead of pressing separate keys for each. I found this very useful in my control configuration, but I see it is not present in Sandstorm. I would really like to see this added back in, as I feel it is a very underrated and useful option.