You will have a great stay in their apartment. We had a great time and they are really kindly. Every evening we had a small chat over everything which was very nice. The bed and bathroom were really good and clean! 02.00 a.m. we arrived at their house and Robert was waiting the whole night while we arrived. The whole time he sent messages how the travel went which was really kindly.
The only thing, if you are traveling via London Stansted it is a long way before you are at their home. The buses are nearby, but it's a very long sit before you arrive in London. The buses are 24 hours so that is perfectly. I would recommend city mapper otherwise it is really difficult to arrive at their house, if you are not well-known in London. One thing we learned this journey, do not travel with Google but choose for City Mapper.