We stayed at Titti and Orla's for a team gathering in London and the house was just perfect for that. We really enjoyed the common areas, especially the back patio to wind up in the evenings. It's not central London but it has good tube connections.
As the only drawback: our stay overlapped with the hottest day of the year and there was no air conditioning (London houses normally don't use this) so was a bit warm that day. Titti and Orla tried to find us some fans but all stores run out. Thanks to them for trying anyway!
Will definitely recommend this place if you're a group and need a beautiful place to stay in London (and don't mind commuting to the centre)