I was there for a week in November. Windsurfed nearly every day in about 12-15kt winds.(mostly Northerly direction one SE) Works in all winds directions, only thing is that it is very tidal. So check the tide times before you go,(better with an incoming time in the afternoon) otherwise a long walk down to the water.
We stayed at the www.burrumsands.com.au (very well priced holiday units) It was right on the water and I left my sail rigged up all week. There are also caravan parks and loads of rental houses available. eldersburrumheads.com.au
If it is low tide it is best to launch from the river boat ramp in town as then not a long walk, otherwise at high tide it doesnt really matter fantastic spot.