This place has a perfect location. It has a metro station just at the end of the street and is within walking distances to the Arc de Triomphe and Trocadero. A small supermarket and a bakery are very close.
Guillaume's place has all you need for a comfortable stay in Paris. Easy to get to. Very clean and cozy.
Only disadvantage is neighbors may be too noisy, but nothing a good pair of earplugs cannot solve.
Would definitely come back when visiting again Paris! :)