I did this trip back in Feb 07 with Alpine Recreation. I actually did the Introductory Mountaineering course and we travelled over Ball Pass on the last day travelling the opposite way of your trip. The Caroline Hut is in an awesome spot. Good food, good guide. We got a visit at the hut by nine very curious Kea on the first night and they were still there in the morning before being buzzed by a falcon and scared off. Did you see any Kea? What else did you do down in NZ?