I also think your taper sounds logical. That said I will say that Xanax Xr is very differet than Xanax . Due to the difference in half life you might need to slow down each decrease to allow your body to adjust to the lower dose that is long acting.

Most Pdocs are actually happy when a patient wants to decrease or come off benzos by choice, and will help in making the decrease as easy and safe as possible. There is risk of seizures when decreasing or stopping Xanax too quickly.

Good luck on your plans to get off them. Don't be discouraged if you need to spend a bit more time while your decreasing.

Good luck