My daughter and I stayed at Romax for 3 nights whilst In Rome. Getting there is quite straight forward, that is if the Metro is working. Use Bus 50 from termini which is a good service.
The flat is cozy and was clean. A small kitchen with a couch bed is suitable for one child. The flat is in an up and coming area a bit outside the main site seeing parts of Rome. If you don't mind a 20-30 min trip into town this is perfect. The area has some funky streets and trendy bars and restaurants which would appeal to the hipster generation. Overall a good place to stay for a young couple.