It's perfect to stay at Giannis's if you are going to Heraklion. The location could not be more perfect, such a quiet street and still next to all the action. The apartment itself is very nice: rooms have air conditioning, everything is clean, two toilettes, huge balconies which we used a lot.
We rented a car (recommend renting from a local car rental - not the international ones) and there is a large parking lot next to the house for 4/6 euros a day which is very convenient.
We also walked from the apartment to one of the bus stations (only 8 minute walk or so) and took a bus to Matala, gorgeous.
Giannis himself is a very good host which will make you feel very welcomed, responds quickly and in general has everything you could ask for in a host.
We would definitely stay again at Giannis's place if we would go back to Heraklion.