With quarternions, gimbal lock is impossible. Also the kinds of simple sums and matrix arithmetic that we use for quarternions are really cheap operations on a

With quarternions, gimbal lock is impossible. Also the kinds of simple sums and matrix arithmetic that we use for quarternions are really cheap operations on a computer. They're so cheap, I wouldnt be surprised if axis-angle was just a syntactic sugar implemented on top of quarternions.