Allphones Arena is one of the major venues at Sydney Olympic Park. It's up to a 14-15,000 seat indoor venue, normally used for major concerts and such.
Basically too big and probably too expensive for the Kings.
The State Sports Center is a smaller indoor arena, also located within Olympic Park. It seats about 4500 and gets a lot of use by the NSW Swifts netball team for their smaller home games. For their biggest games, where they get 10-12,000 people they hire Allphones Arena.
Olympic Park was built to house the 2000 Olympics and is home to ANZ Stadium (86,000 seats), Allphones Arena (previously known as Sydney Superdome) and Sydney Showground (sit of the Royal Easter Show and incorporating the Dome, a round space used for dance parties, conventions and exhibitions, it can be set up with temporary seating for games and would hold about 7,000, but like much of the Showground is in very heavy usage for exhibitions and trade shows like the motor show, mining expo and the good food and wine show).
The rest of Olympic Park is home to the Aquatic center, Hockey center, Archery center, Athletic center, Tennis center, the previously mentioned Sports center and increasing amounts of offices and high rise apartments.
A lot of it is parks and gardens, and it's served by a dedicated train line, bus links, a ferry wharf and has about 12,000 car parking spaces.
Probably the thing most people don't like about it is that's it is located right in the center of Sydney, geographically speaking, which means people in the east near the CBD don't like travelling there because they see it as too far away, the same as people in the west, the north or the south of Sydney (urban sprawl for the winz)
It's a pretty good facility, lots of venues and stuff all in one place, but for a lot of people they don't want to change their routine and the Kings relocating to Olympic park at Homebush is just that, hence the wailing and gnashing of teeth.
in the end it's not like the Kings have a choice and any real fans going to have to suck it up.