Place was a good size for our family of six. Elena was also lovely and left a few essentials for us when we checked in.
The flat has a few drawbacks. It could have been cleaner (dust under the tables, some plates had crumbs, spoiled vegetables in the fridge). But Elena did let us check in 45 minutes early so perhaps she didn't have time to do the thorough cleaning.
The bathroom sink leaked a bit, and there was a broken fan that had exposed blades which was a bit risky with two small kids. The flat also gets pretty stuffy unless you leave the doors open in the bedrooms and have to them close them and the blinds by 7am or the sun can be a bit overwhelming.
All in all, I would still recommend this place as the issues are not major. It's better for people traveling without kids though as there is a lot of glass everywhere.
We had a great stay in Heraklion!