While it doesn't sound like a huge study, I do tend to agree with those conclusions, having worked with adjustable desks for a few years now, due to orthopedic problems which make it uncomfortable to sit all day...

I much prefer to be sitting when in "flow" for coding, but I stand when doing more bureaucratic tasks. And many times, it is nice to just be able to switch positions every few minutes, more so than trying to be on my feet all day.