The flat is very close to frequent public transport to the city and to Messukeskus. It is also close to restaurants, a supermarket, and bars. It was clean and felt welcoming and comfortable. It has a small, useful kitchen with an induction hob, good for cooking quick meals. Like all places, it had its quirks (little lighting, no wifi), but was a pleasant place to stay. The only inconvenience was that there was only one key between three of us. We would stay there again.
Vincent's apartment is exactly as shown in the pics, and the location is excellent. I was travelling with my family (wife and 2 boys, 3 and 6) and we all fit in just fine. The apartment had most of the items we need, and Vincent had even left some bread etc for us. Communication with Vincent was easy and he responded to all my questions in a timely manner. Now - things to improve: the apartment does not have wifi, the vacuum cleaner was finnicky, and for some reason we did not find the remote to the tv. But, all things considered, I can easily recommend Vincent's apartment to anyone traveling to Helsinki. You can easily get a prepaid net connection to your phone, and you should not watch tv on your vacation anyways :-)