The Old Exchange? f**k me. Never ever go there.
Ever since the new owners took it over, renamed it to that shit name (previously the Electric Light) they have ruined it. The Old Exchange? Sounds like I'm heading to a 1890's pub.
Went there the other week, bar manager gave me a 'tour' of their 'renovated' back room where they have literally destroyed it. Bar looks like it's made from pieces of wood found on the side of the road. She couldn't even turn on the lights since half of them weren't working. Crowd outside in the beer garden was full of feral bogans. 2 guys wearing Fubu shirts and wu-tang trackies. Rest of the crowd were f**king horrible.
That place is a f**king dump. The manager even admitted that the new owners "could barely afford to buy the place" let alone keep it half respectable.
Tap Inn is a quality pub. Sugar on a Friday/Saturday night on Rundle St is real quality. Older crowd (early 30's and up) and awesome house music. Most places on Rundle St are decent. Also the Union is pretty good, as is the top room there.
You can make your own judgement about Hindley street but it's pretty tame compared to other states around Australia.