We stayed seven nights in Blue Mountain Bund Youth Hostel and we would recommend this hostel for other travellers. We first stayed in a room on the 7th floor. The room shared bathrooms with only 3-4 other rooms. After half the time, the 7th floor was closed since the hostel wasn't fully booked. We were moved down to the 6th floor where everything else is. They even compensated us and upgraded our room! The 6th floor has a huge terrace, a pool table and nice common area. No outside food tho.
We stayed 7 nights in a double room Hi Inn New Guanqian Branch. The hostel seems to be an old children's hospital. There are loads of rooms resembling cruise ship cabins. They're tiny, but functional. The bed was a mattress on the floor. There wasn't much room for bags. There's a common area with free pool table and foosball and computers and tables and chairs. No food is served. The staff was helpful and friendly, and managed in English. Impersonal and not atmospheric. But ok.
Zhengjia hostel/hotel actually has two (at least) properties just beside each other. The first one, coming from west through the tower, is more hotel-like while the latter seemed to have a more hostel-like vibe to it. We stayed two nights in a double room in the former. They seem to share staff and kitchen at least. Part of the staff spoke some English, some better than others, but enough to be able to communicate. Overall the staff was friendly and helpful, although not overly service-minded.
We one night in a double room. We would highly recommend this place. The hostel had opened only a couple of months ago when we were there. Hence, everything was brand new. The double room and its toilet were big and clean. The beds were very comfortable. The common area was big, had a pool table, a game console (Wii) and a bar. Staff was super! The outside of the hostel is a bit dirty with debris, so walking across the parking lot and up the stairs you're not expect a hostel this nice!