How is being stationed at Fort Belvoir for a 68W?

Fort Belvoir is an excellent place to be stationed, IF it's not your first duty station. For those coming straight from AIT, it's a place to learn your craft, but you'll not learn any of your Soldier skills and those will wither while you're here. It'll be a disservice to you as a Soldier for when you proceed to a field unit.
That said, the National Capital Region is a unique opportunity. If you can think of something to do, any activity, it can be done here. And in the unlikely event that it cannot, there are many travel options on how to get there.
The cost of living may be high, especially the closer you get to the epicenter (The District), but if you choose to live in the outlying areas, you can easily make your dollars work for you.
The District is full of free activities, and it's a great place for families.

As with any duty station, it'll be what you make of it. When you arrive, ensure you grab with gusto any tasking that enhances your knowledge as a 68W. Take the time to improve your civilian education and take as many military schools as you can.

I'm currently working in the Dermatology clinic at fbch. I do the same things that our civilian lpn's do (local anesthetics before skin cancer surgeries and cyst removals, occasionally doing sutures, freezing warts, setting up the UV box for psoriasis / eczema/ etc. patients. The clinic hours are 0730-1600. I also take online and night classes and have my associates degree. (Full time parent). There's plenty of schools around here (within an hour) for promotion points (Combatives I & II, bus driver, forklift, word processing, mail handler, etc.) Housing is so much better here than it was for the 5 years I was stationed at Fort Hood (4 br, 2 1/2 BA, garage, carpet in living areas, hw laminate in wet areas, black appliances, privacy fenced back yard, free landscaping in front, etc.) Traffic around here is atrocious, and that's probably my only complaint. If you go to fort belvoir, try to request an outpatient clinic, we get snow days, some training holidays, and federal holidays off.

I personally wasn't stationed at Belvoir as a 68W but I was at Rader Army Health Clinic on Fort Myer. Being in the DC area is a once in a lifetime type assignment. Not everyone gets stationed there so early in their career. Make the most of your time there. Fort Belvoir is an extremely nice installation. You are right down the road from Mount Vernon. You are about 23 miles from the Washington Monument. There is always something to do there! I hope you have fun. I loved being in the DC area