I am not Mike. But I use a standing desk. It took me a few weeks to get fully adopted, but now I can stand (or move in place) for several hours, if necessary. Usually I take short breaks though.

And actually, the ability to take short breaks and walk around is something I really cherish. Removing the (small) barrier of needing to get up has really helped.

But you can not read too much into my experience report with the standing desk: I took up weightlifting at the same time I got my standing desk, and so it's hard for me to say which change was responsible for which improvement.