I am a huge proponent of standing work stations and office ergonomics in general. Excuse me if I get a little fanatical about it.
I highly recommend using a standing work station for all the benefits. I have more energy, I can move around a bit, if I have music you might see me dancing in my cube. I also have a tall stool so that I can sit for awhile if I get tired of standing. If I didn't have a standing workstation, I probably would have quit my office job a long time ago. Seriously, the ability to stand and move around has greatly improved my working situation. There are many health benefits because the human body is not designed to sit all day. We need to move around, and 30 minutes of exercise might not be enough.
Sitting all day is a just a total sap on energy. When I first moved into an office environment after working in very physical jobs, I could feel my body turning to mush. So I came in early one day and figured out how to adjust my desk.
I made that $22 Ikea standing workstation. Wasn't bad for awhile, but it has some issues. It's cheap and can't support much weight, so when I developed a tendency to lean on it, the shelf broke. And you cannot adjust height at all, so you cannot even make minor adjustments if you decide to sit for awhile. If you are slightly taller than average, it's hard to find a chair that will high enough so your monitor/keyboard are at a comfortable height compared to your standing.