I highly doubt that you will be able to find another hostel in prague so clean and with such a friendly staff. With an overall look of a tree house, the facility has an awesome feel about it: it's like you're actually living in a tree and even the showers are decorated accordingly!
The spacious rooms and public areas are bound to get you in touch with fellow travellers, if you decide to cook or eat together.
The staff has been amazing, and they even took the time to help me send some items I forgot at their hostel.
In other words, as their name suggests, they make your day harmonious!