Lisi and Luis are wonderful. Well, I only met Lisi, but after meeting her, Luis must be wonderful.
The apartment was perfect for parents and I during our weeklong stay in DF. It's cute, clean, and intersting. Very close to everything you need in Roma Norte.
When you arrive, you'll wee the work that Lisi and Luis have put into ensuring you have an excellent time. So much info on where to eat, how to get around, and what to do, if you didn't have a concrete plan, you'll have no problem putting one together.
The street is quiet, and on the same block as both Lalo! and it's sister restaurant, Maximo Bistro (GO!)
Lastly, Lisi and Luis are really nice. My mom had some health problems when we visited, and she ended up having to go to the hospital. Lisa checked in regularly to make sure she was doing alright, and even made some calls for us during our emergency.
Stay here. I don't think you could find a better value, and you certainly won't find better hosts. And take advantage of the rooftop!!