Probably one of my favourite hostel stays in the South Island. I stayed in a total of three Haka Houses over my NZ trip, but I think Franz Josef was my favourite.
Obviously the location is incredible and proximity to the glacier can't be beat. The kitchen is massive with lots of facilities and storage, the games room/lounge/dining room and movie room are all pretty generously appointed. It also lends itself well to socialisation and I think I unexpectedly made the most pals passing through here (and Arthur's Pass).
The front desk staff are really nice and are there from 0800-2000hrs. There was no onsite parking (paid) available due to summer high season but plenty of free street parking available.
All Haka Houses I've stayed at have the same bunk style with two AU/NZ electrical sockets as well as a USB-A and USB-C port, plus lockable storage that has the same thing inside (bring a decent-sized lock, I had some tiny ones and had to buy a medium one). This is a great idea. You can charge things while you're away and they're locked up, and if you don't have an international adapter you can use cable only. The privacy curtains are a good touch as well.
They also have all had the nice enclosed showers with a detachable showerhead. And bath mats!
I also think I had my best hostel sleep here, the beds are decently comfy and I got really lucky with roomies - three other women, none of us snored.