Posted about my standing desk about nine months ago. After talking with my brother I felt like I should post an update for those who still haven't taken the plunge.
My post from last year is here.
I spend anywhere from 6-8 hours per day at my standing desk, and it gets used for work exclusively. I've stopped any sort of gaming, mostly for lack of time, and I've taken to drawing on my tablet there as well. It's where the majority of my work gets done, unless I'm ill or something.
The desk I'm using has a keyboard tray which is handy for storing my tablet, external hard drives, extra mice, and so forth. I highly recommend rotating keyboards and mice to keep your hands and wrists from getting to used to one or the other. I don't know about the orthopedic benefits, but it helps me stay focused and aware of my posture at the standing desk.
Edit: It's worth mentioning the importance of shoes. Nothing makes my back hurt like working at my standing desk barefoot. Wear good shoes when you're at your vertical workspace.
It's easier to maintain my weight. I don't feel like my weight is in constant flux. While I haven't shed mad pounds or anything, I do stay pretty much the same.
My mental health has improved, and I'm more focused. I'd actually like to figure out a way to have more table space for my notes and such. I'm not getting rid of my bust of Odin though.
Reduced pain in my hands, wrists and shoulders from long hours at the keyboard. Posture is really important and you've got to stand tall, back away from the desk, and avoid leaning on it to get the benefits I think.
It helped me sleep better for the first few months, but now I think it does the opposite. The pair of twenty five pound dumbbells sitting by the desk help.
My back hurts a little bit if I forget to take breaks and walk around. Sometimes I'll just disappear into my own little world making text and come out of it with a back ache. If you do a standing desk, make sure you take a break every hour or so. Walk around the block, rake some leaved, trim the shrubs, take out the trash, something.
If you find yourself fighting with your weight and being sleepy at your desk, I would recommend giving a standing desk a try for three months. I'm not a healthcare professional, and I would recommend consulting a doctor if you've got any condition that would mess with you as a result of standing for long hours before trying a standing desk.
It doesn't have to be expensive. My standing desk was a cheap $80 desk you buy at the office big box store and $15 worth of cinder blocks from Home Depot. There are plenty of far more expensive solutions out there if you think the cheap will clash with decor.