Went through Williamtown Airspace a couple of times a few weeks ago, I was VFR, didn't use the VFR corridor because I didn't feel like getting pummeled in the bumpy conditions and had no real problems at all getting a clearance to be honest, could be because I had a Flight Plan in the system, though on one of the times I was way off my originally planned course because of some weather near Coffs but once again, no real issue.
It certainly helped when I needed to divert into Coffs Airspace because of said weather, called up Centre, advised them I was having to divert due weather and needed a clearance, no hassles there either.
I know it can be a pain but I really see no hassle in putting in a quick Flight Plan before you go even if you're not planning on going near Airspace, because if you do it'll make your life a lot easier it seems.