Wonderloft was an ideal place for my stay. For the low price, you are assured a decent dorm (in the form of a capsule bed, though I don't know why they call it capsule. It's quite large and spacious, with a locker inside).
The staff are extremely friendly. Especially Sandy, who was very accommodating and friendly, patiently helping with all enquiries and helping book taxis..
The location, in my opinion, is the highlight. It's located right next to Fatahillah Square in Old Jakarta. There are quite a few cafes just a couple of minutes down the road, in the square. I wish the staff would let you know about this amazing place just behind the hostel, as I found it through research, and then was extremely surprised to know it's right next door.
The rooms can can get a tad bit warm, but it's not too bad. Overall, a great stay.