in DC? Which has more impressive food court/shops? Have never been to Old Post office,are the views of DC as good as advertised?

I prefer Union Station. The Old Post Office is not that great. The view is fine and might be worth going up if you have extra time. However, Union Station has so many places to eat and lots of shops too. The Old Post Office is very "touristy" and there's not much choice for food or shopping. Plus, it doesn't provide a lot of overflow for the crowds. We looked forever for a small table for two so we could eat our lunch. Union Station became a place we went to almost everyday on our trip to DC since the metro stops there. It's really easy to get into and you can always find great food. Try the pizza place(Pizzaria Uno, I think) or Corner Bakery!

My vote would also be for Union Station. When I visited DC, I believe I went there every day - it is just very convenient. Oh, and there is a bakery downstairs that sells the best soft pretzels I'd ever had!

For views, definitely go to the old PO. For food, go to Union Station.

We found the Pavilion much quieter, for a quick bagel & coffee, but the selections, and shopping at Union wins over the pavilion.

We thought the clock tower view, and the talk about the history of "the old tooth" was great. Only for no money in the budget for demolition (for years!) that kept this building from being torn down. And only because its architecture style didn't fit into the rest of the "Federal Triangle". See it if in the area, but don't go out of your way for it.

Union Station for food & shopping, Post Office for a quick side trip while walking along the Mall.