Well, standing cause varicose veins - because a close relative just needed surgery because of standing too long - and she doesn't have the healthiest relationship with her butt, so what gives? Are standing desks really healthy or not?
My neurosurgeon for the procedure was fantastic, but he basically said "humans aren't made to be in any position for prolonged periods of time". His recommendation was a sit/stand desk and to occasionally but consistently be changing things up -- re-positioning, standing/moving, using an exercise ball occasionally, etc..