We stayed at Alvin's last April for two weeks and we had a great time.
The flat is a bit small but is perfect for two people. You have everything you need and the location is amazing. There is a Tesco one block away and the nearest tube station allows you to reach all the major atracctions.
We didn't met Alvin but we met Kwong and he was great, really helpfull and nice.
I would definitelly recomend this appartment.