VSI for these calculations is either GSx10/2 or straight GSx5. Use whichever you can wrap your brain around. This method corrects for the TW and HW but as stated before may not be the best option.
If you are flying an Airbus with 100 knots or more on the tail and you are descending from a very high altitude in managed descent you may get close to the MMO limit even with the protections when the winds start shifting during the descent.
With a 100 knots HW your VSI may only be 1700fpm or so and may not be the most optimum descent even though it is 3 degrees.
Now flying VIP pax I will often do the math for a more shallow constant rate descent if I'm not expecting turbulence or CB's in the descent so it's more comfortable for them.
Just my 2 cents.
Oceanic