Mark, Chris is correct, of course.... on both counts. Portsea is a really fun track - still. Without getting into arguments about order, the top 5 courses on the Mornington Peninsula could easily include: National Old, National Moonah, St Andrews Beach, Portsea, Sorrento, Dunes...and that's not looking at Moonah Links etc etc.
I know you are playing National Old & Moonah already. As much as I like Portsea, next cab off the rank should be SAB. Its just a matter of how many rounds you want to play down there.