The appartment's location is great. It's not in the midst of hotels and "touristic" places. Though it beeing little away from the sea (max 10 min by foot) it has everything needed! Little down the road is a small supermarket and next to it an amazing greek taverna (four seasons). We can only recomend to try it out. Be aware the portions are plenty :-)
If you want to go to the beach, try the Kastelia Beach, it is small and stony but the water is amazing.
The apartment has everything needed and was very clean. It looks exactly like in the pictures! Dimitris who lives just next door was realy helpful. He even picked us up at the aorport (we did not rent a car)!
We'll keep Karpathos in very good memory and will probably go back for a week.