If you are looking for a fast half marathon run before Rotorua next year, we are having the inaugural Fitness Fusion Ohope Half Marathon on Sunday 4 April next year. It should be an excellent course for a personal best!
http://www.ohopehalfmarathon.co.nz/
There's also a 10k run/walk and a 5km Doggie Dash. The half marathon will be purely on the road while the 10k and 5k Doggie Dash will include some beach action.
Cheers, Paul :-)