I highly recommend Dorota's place. It was one of my best airbnb experiences.
Though the apartment is small, it is still very cosy and practical. You have also a small balcony, where can enjoy lunch and coffee. You can prepare food in the kitchen. The falding bed is quite comfortable, though a bit small.
You'll have to walk 7min till the tram station to get to the city center, the ride is fast (costs 1,2€), around 10min. Nearby the apartment you have a very nice café, focacciaria as well as a good and not expensive restaurant (ask Dorota).
The communication with Dorota is perfect. You'll get a quick answer for all of your questions.