Mark was an amazing host and the place is absolutey beautiful. If you're thinking about staying here I'd say absolutely do it. The slight splurge for my sister and I was so worth it. The views are incredible, the rooftop amazing, and the aparment was pleanty enough space for both of us. extra towels, blankets, and room in the closet helped us keep everything organized. Not to mention Mark was so kind. He helped us find parking when we first arrived, was quick to respond to any questions we had, and was super friendly in person.
The reviews about the stairs are true, they're a bit of a workout. But if you can't pack light its still very possible to get suitcases up the 3 flights, it just takes a little work. My sister and I were both able to get two suitcases up between the two of us.
Overall, our first time stay in DC was made so much better by staying here and I'd absolutely recommend it.