I'm from Italy and I've been at Mundo last week with one friend! The Hostel is located in a strategic position, closed to the Old Town, the Jewish area and the Railway Station.
The twin room ensuite (called Cuba) was nice and clean, also the bathroom was very clean and spacious.
Every morning we had a great breakfast in the common room! This area is the heart of the hostel, it's easy to meet people and spend nice time chatting.
Just one word for describe the staff: SPECIAL! I've never been in a Hostel like that.
I suggest you to go there, also for the good prices ;)