Niko's place is very nice, it's small but have everything needed, from the kitchenette to the nice bathroom and an extremely comfortable bed. It was very easy to get the keys and the lady that gave us the keys and got us to the apartment gave us also a nice recommendation for a place to eat and told us about the carnival parade on the next day evening, which was very kind. The apartment is literally 2-3 minutes from San Marco but still in a calm area, it's also close from other major points of Venice. All in all it was a great trip, there weren't any problems, so I strongly recommend stay at Niko's.