We stayed at Ruben's place for 4 nights and we enjoyed our stay very much. The place is small, but we knew that when we selected it so no surprises there. Everything you need to cook is there along with cleaning supplies! The apartment is very modern and tidy. We loved the TV which had some English shows and the overall convenience of the place.
The location is awesome; very close to Nation metro station and lots of cafes, convenience stores and a grocery store all close by. For the price, you can't beat the location. We ate at Le Canon and Extra Old Cafe which are along the same street, and really enjoyed our meals. Great service and there are LOTS of locals in them so we figured the were a sure thing and they didn't prove us wrong.
There were only 2 things we didn't enjoy so much:
1- The wifi connection is very poor. I am a graduate student and couldn't log on to my school's website to do work the whole time. If you just need to do some texting and google maps, you will be fine! But more than that, you are taking your chances.
2- the bed is great if you are travelling alone or with a partner for 1-2 nights. Otherwise, it made a lot of noise and wasn't the most comfortable of sleeps. It definitely did the job and could be worse, but could be better as well.