Ismael's place is in an excellent location, right next to the Austerlitz station and across the bridge from Gare Lyon. There are lots of places to eat and sites to see with in walking distance or a short metro ride.
His place is on the fourth floor and there is no elevator also the last set of steps is quite narrow and the ceiling slops. So I would not recommend this place to folks that are very tall or large.
Over all I enjoyed the stay very much.