I used to live in Finsbury Park and on my stretch of road we had many independent supermarkets and a small Tesco and Sainsburys and they survived quite well. The difference being is that the independent supermarkets were well stocked with fresh herbs, spices, fruit and vegetables and often better priced. I think that sadly that is the difference to Honor Oak and Forest Hill because apart from the deli (which is lovely but a bit pricey) there really isn't anywhere that offers a selection of these things so it means that I need to visit Sainsburys in FH (of which I'm no huge fan) if I want more of a selection. Personally, I think it will be a good thing but if I were an owner of any of the other shops (with excpetion of the deli maybe) on the parade the I would be worried and I think it will have a very negative effect on these businesses.