Hey CC - cant give any advice here just wanted to say enjoy the City to Surf. I have done that one a few times and really enjoyed it (hmm except those hills near the start).
Is the half part of what use to be called the Perth Peoples Marathon?
If its the same one I did the Marathon years ago and it was really well supported and organized.
I guess the question is what distances are you running at the moment?
If its not far off the half distance I would say go for it.
The most effective way to do it, is to do it.
Amelia Earhart
2005 Trek 5000 road/Avocet 02 40W
2006 Colnago C50 road/SSM Atola
2005 SC Juliana SL mtb/WTB Laser V