Marine was very helpful, and answered any questions we had fast and effectively.
The flat was exactly as described, including a fully equipped kitchen, fresh towels and bedding. And is in easy walking distance to the underground. It was definately suitable for longer stays as we were there for a month.
We did have one big problem with the apartment though, which is that it is overlooking a huge building site where they are building a new power sub station, this meant there was extremely loud banging and drilling from exactly 7.50am - 5.30pm six days a week. We weren't warned about this in advance and the work looks like it will be going on for a couple of months (we stayed in May) The flat is double glazed so you can cancel out some of the noise, but that means keeping all the windows closed in a very warm flat in summer. It is possible because the site is new that the host wasn't actually aware of the work and therfore couldn't have warned us in advance, but it was quite unpleasant.
I would definitely recommend the flat, and Marine as a host, but I would avoid staying there again while the building work is still going on.