After one week, I am pleased to report that I still love my VariDesk. I am still standing for 20 minutes and sitting for 10 when in the office, although occasionally I extend the standing period to 40 minutes. If I am eating lunch at my desk, I may give myself a 20 minute sit until I finish.
I can feel my new posture in the muscles in my back and flanks. Clearly standing engages them much more than sitting. I hope my plank time starts improving.
The other big change is that I have more trouble sitting still. In clinic today, while waiting for a student to finish interviewing a patient, I found myself standing and pacing while I read an article on my iPad. Sitting in that situation just feels wrong somehow.