We stayed in the Pikk Street apartment for 4 nights and we didn't want to leave!
The apartment was absolutely huge, with a log fire. We looked out the bedroom window and across the street was the Oleviste church. Quite frankly, the best view I have ever had from my window! We also got a complimentary bottle of wine as it was their 12th birthday.
The house smelt of log fires, which to me was a great. It was really cosy and comfortable, plenty of bedding and towels provided.
We were on Pikk street in the Old Town, about 5 minutes walk from the old town square, so it's location was excellent. There are loads of shops and restaurants along Pikk so you don't have to walk far to get great food.
Overall, I cannot recommend this place enough. We loved Tallinn so much we plan to go again (not something I normally want to do once I've seen somewhere). It hasn't been spoilt by tourism yet, so it's best to go now. If we do come again, I will go this time of year, and I will definitely use Old House Apartments again.