I loved this place. It's in a very quiet location but you can easily walk to where the action is; there are different restaurants, parks, etc within a 10 or 15 minute walk in any direction. I am a woman and I was traveling by myself and felt perfectly safe walking around the neighborhood at night.
A couple of notes that I didn't see mentioned in reviews before: although a lot of people mention all the stairs, nobody says how many: there are four flights (but they are short flights). Also, there are multiple areas you will hit your head if you're tall, I'm 5'5" and there were a couple places I had to duck a tiny bit. Lastly, I was told to ring the bell when I arrived and I couldn't actually figure out where the doorbell was for a little bit. It's just a square plastic box you push on, not a traditional "button," and it's set up a little high to the right of the door.
The internet connection was good when I was there and the apartment was chilly but lots of extra bankets were provided so I wasn't cold at night. The bed is VERY firm (it's just a couple of slabs of foam) but I found it comfortable. The shower is absolutely lovely but the water pressure isn't great (only a problem if you're trying to rinse shampoo out of really long thick hair).
All in all, I would definitely stay here again. It is an excellent value and the location just can't be beat. I love how much character the place had as well, if I wanted to stay at some luxury place I would have booked somewhere else, but I booked Penelope's because of how adorably Mexican it was.