We stayed at the townhouse for a week in August: 2 adults and 3 kids (aged 11, 9 and 6). The owner, Ferdinand, told us that he used to live in the house, and you could tell - it felt like a home, not like holiday accommodation. There was plenty of space, and each room was well-equipped. The free wifi was much appreciated; as were the guide books and tourist leaflets left in the house.
The location is superb; walking distance from everything in Delft including the station. By chance our stay coincided with 'OWee', the Freshers' Week for new students at the university, which meant plenty of free entertainment right outside the window. The centre of Delft is beautiful, full of historic buildings, buzzing cafes, independent shops and of course canals.
We came without our car and used the excellent Dutch public transport to get around: it's worth researching the 'OV chipkaart' in advance if you plan to use this as you pay a surcharge to use paper tickets. We spent a day in Amsterdam, a day in Rotterdam, a day at the beach (Scheveningen) and in Den Haag. We could have done more day trips but preferred to enjoy Delft at a leisurely pace: there's loads to see. The Science Centre in Delft was a particular hit with our kids - we were there for 3 hours and wished we had longer.
Ferdinand was extremely helpful and quick to respond to emails. He is very proud of his lovely house - with good reason. Highly recommended.