Prime location, but not much else.
I've said this before, "Your expectations are directly aligned to the price you pay."  Again this was true of Courtyard by Marriott at Dupont Circle.  We paid $152 a night during April break (through a bidding website) and I expected a bit more.
First the pros:  Clean hotel and rooms, comfy beds, nice strong showers, fairly quiet heat/AC system,  plenty of space (see picture) excellent safe location, parking was reasonable considering we're right in the city ($12). There is a large business center with multiple computers and printers. There is Starbucks Coffee (for sale) in the little hotel cafe. The red line metro was 2 blocks down from the hotel - it was very convenient to dash in and out of the attractions.  We could be at Capital Hill / the mall in less than 10 minutes.  There are also a variety of food options on the street.  We felt perfectly safe walking back from a Nationals Game at 11 pm up this street.  It might remind you of the East Village in New York.
The view from our room on the 6th floor was fine, but not worth spending the money to stay here.  It was nice seeing the Washington Monument way off in the distance, but no big deal (see pic).
Cons:  No WIFI in the rooms, only on the first floor.  Again for this price, that should be a given in this day and age.  That would be the first thing I'd fix if I was running this hotel.  You CAN plug in an ethernet cord for access in your room, but that won't work for ipads or laying on your bed to surf.
The male front desk staff (two dif men on dif days) were curt and scowled at most people.  When they wished you a good day their eyes never left their computer monitors. When you asked a reasonable question they rolled their eyes. By comparison, the women at the front desk were more genuine and friendly.
There is no continental breakfast, no bowl of fruit - just $$$ snacks in the cafe.  There is free coffee in the lobby, but it was the worst coffee I have ever drank anywhere in the world.  A weak, oily, salty brine I would expect they drank on pirate ships!  I was so shocked I tried it on 2 different days in case someone just made a mistake - nope just as bad both days.  It appears to me that the staff take a very cheap approach to these amenities.
Although it was 89 degrees out (April 17), they said the pool is only open after Memorial Day -  not a big deal to grownups, but the kids complained about this every day.
So all in all, it wasn't horrible.  Just disappointing.  If you've booked this hotel here are a few tips that you might find helpful. 1. There is a RITE AID across the street and we bought all sorts of things there: a case of bottled waters, a pint of ice cream for dessert, orange juice and milk - much cheaper than getting those things at stores. Also we enjoyed grabbing breakfast at Bethesda Bagel - reasonable and really good. 2. There is a SUBWAY 1 block down from the hotel, and that can make for a quick lunch or dinner - just remember that you can't bring food or bottled water into most attractions, so eat first. 3. We arrived by plane in Baltimore and it was VERY easy to get this hotel (Airport Shuttle > MARC train>Union Station > Red line to Dupont Circle.) It took about 45 minutes, cost about $15. 4. The metro doesn't start until 5:30 on weekdays. We learned this the hard way and missed our MARC train back to Baltimore. 
Have a great trip and check out my DC post about our 4 day trip - Lots of good tips and mini reviews of attractions ( Museums, Arlington, Ford’s Theatre, Cap tour, Ben’s Chili Bowl, Chinatown, going to a Nationals Game.).  Happy travels!