My girlfriend and I had a wonderful time during our two day trip to Amsterdam: partly because of Erik and his nice apartment, partly because of the great city Amsterdam is. We arrived a little early, and Erik was still finishing up our room when we rang the bell. He said he wasn't expecting us for another hour, but was very friendly nonetheless: he showed us around, explained the apartment and what was expected from us. We dropped off our bags and he directed us to a free parking spot in the vicinity. He warned us that houses in Amsterdam are noisy, but we didn't notice that much from the neighbours. A bit of a warning though: the room isn't very dark, so if this bothers you bring a sleeping mask.
Erik seems like a very relaxed guy to me: we could always go knock on his door to ask for something, he brought us some croissants in the morning (unexpectedly, thanks again :)), he let us have the room for as long as we needed it because he wasn't expecting guests the day after.
Although the location might scare you off, the house is located in a residential area on the other side of the IJ, I wouldn't let this bother you at all. Free transportation runs very frequently to the central station (on the side of the city center) and there are two nearby stops (less than one kilometer away). You can be in the city center in less than half an hour, and it is a way to escape the city after a very busy day.
In conclusion: I would greatly recommend staying at Erik's place if you plan on a trip in Amsterdam.