I tried a standing desk. It boosted my productivity for sure - when I wanted to procrastinate instead I just switched between sitting/standing and kept working.

It also created a couple of health problems.

First, I started to feel pain in my left shoulder. After a while I realized that it's caused by leaning on my left arm as a way to let my feet rest.

Then, I started to feel tingling/numbness in one of my knees. It persisted for weeks until I stopped using a standing desk.