We have two shared treadmill desks at my office. I usually walk on the LifeSpan because it can go a bit faster, but sometimes that's occupied by a coworker so I have to use the Steelcase instead -- if it's available. I use these desks a lot. I also successfully lobbied to get a VariDesk Cube 40, which occupies an empty cubicle next to mine, just for standing.
I want a treadmill desk at home, but that's not in the cards yet. I do have a Lorell Sit-to-Stand monitor riser similar to the VariDesk at home, but I don't have a treadmill. So I can only stand.