Yeah, we were there in 2013. You'll struggle to get anywhere near the bridge. We bought tickets to watch it all from Taronga Zoo and had great views with live music and took picnic/booze. Had a great night.
We stayed in Manly and took the ferry (cheap) in and out of Sydney each day which has great views too. Bridge walk is a must do.
Twice. Last time 2011 when we won the Ashes 3-1. Family and friends hired a boat and had a party in the harbour. Just a fantastic way to watch the fireworks.