I tried it, not with a proper standing desk but simulating one the best I could one day.
I did like it a lot, and would spend a good bit of my day standing with the option but, it wasn't something I found I could jump right into. I don't simply stand all day, so I am just not used to it and it was painful after a while. I found myself needing to sit.
That said, I did feel that if it was part of my normal work environment, that I could transition from seated to standing, I think I would use it frequently.