We adored our time at Adelaide's gorgeous flat in Walthamstow. The house was super homely and made even more so by being greeted by resident cat, Tiger, upon arrival home after long days in the city. The flat is comfortable, well appointed and stylish. For our purposes, visiting friends and family in north London, it was just perfect and we would stay here again in a heartbeat.
This flat isn't super central in London and the journey to and from tourist destinations can be long, especially during peak hour - but London is so well connected that we didn't have any issues with getting to and from the city. (Just something to consider if your main intention is to be in Central London).