Elo's amazing location that can't be beat. Conveniently near both St. Michel / Notre Dame and Odeon stations, we got to Versailles directly via RER train with no transfers. There's many metro and bus options for easy access to other parts of the city (e.g., Gare du Nord, Montmartre, CDG). St. Michel's RER platform has an elevator if you have heavy luggage.
Despite its central location, Elo's place is very quiet. The apartment is on the third floor with no lift, although this is typical for Paris and did not matter for us too much. Elo also responded to all of our questions very quickly. Thanks for a great stay!