I live around the corner from this place, and it is awesome! Seriously, maybe 5% of the reason we bought our house was because it was super close to this awesome convenience store (don't judge.) The beer & wine selection here is solid, and they have all the staples you need if you're halfway through baking a cake and realize you're out of milk/eggs/whatever. They also carry a small but really helpful selection of produce - limes, lemons, tomatoes, and onions mostly, which often turns out to be all I need.
Best of all, my understanding is that the owner and his family live upstairs, so they're able to be open even during snowstorms and other crazy DC weather.
You do pay a premium for the convenience factor on groceries here, but it always seems worth it to avoid getting in the car and driving to the supermarket &c.
P.S. You may know Iva's Market as Sligo Beer & Wine, or 730 Sligo Beer & Wine. A bit confusing but it is all the same place and if you need to pick up some beer for a party you should go here! read more