Klara's apartment is beautiful, clean, and very spacious for NYC. There is a large TV that was easy to use, a big kitchen to cook in, and a spacious common area. There was even shampoo, lotion, sunscreen, etc. provided for use. The pictures of the unit were completely accurate, which can't be said for many other apartments on Airbnb. The location is great in terms of being close to the subway, Central Park, the Met, etc.
The main negative part about it in my opinion is the building itself, which is not at all nice. Not only is it under construction (and both of the main doors downstairs are thus left unlocked at all times, which doesn't seem very safe, especially in a potentially sketchy neighborhood where there were groups of men hanging out outside the building late at night), but it also smells very badly and just feels gross in the main area/elevator/stairwell. The entrance is also on the basement level. Clearly the building itself is not kept up well (it didn't actually even seem like construction was even happening while we were there/it doesn't sound like there's been much progress made on this over time, based on other reviews), but of course there is nothing Klara could do about this. If this is important to you though, this may not be the place for you. The unit itself is great, though, and was perfect for my needs! The elevator was also working.
The only other potentially negative experience is getting access to the unit. I had to connect with a neighbor who had a key. She was easy to reach and nice, so it worked out fine, but a lock box would probably be ideal, in case the neighbor isn't there. I also think the neighbor has her own key, which has the potential to be a little scary (though again, she seemed very nice and never once bothered us).
Overall, we had a great time, despite the sketchy building area. Once we were in the actual apartment itself we felt like we were in a completely different, very nice building, and it was also very quiet inside. I definitely recommend this apartment overall!