The city YHA is a backpackers very close to the centre of Perth and well managed. It's central location makes it a good place for exploring Perth.
The hostel itself is well maintained (as good as this is possible in an backpacker) and has reasonable facilities. Sadly it's located right beside the train station of Perth and therefore you will have some train noise ...
In general it's a cheap and well maintained backpackers, if you want some high sophisticated accomodation with high standard a backpackers is probably not a good choise, if you want a cheap and well maintained and clean locations this spot is perfect.