In an open office configuration it's pretty nice. I have a "standing" desk at Dogpatch NYC (it's really just the standard Ikea desk all the way up + a printer box for my laptop) and beyond the general standing benefits (more mobility, less back pain, etc.) it's also nice to look up and not be staring at a screen and actually see what people are up to (which is mostly staring a screens).

The main downside I've seen is that greater mobility makes the kitchen (which is only 15 feet away) way to easy to get to. I think I've replaced the extra calories I burn with more snacks.