Well, I made it back alive! Looked doubtful for a while... the 2 guys I went with train for this stuff! 12 hours for my first day was a bit much for my body I think. Paid for it with a very tired and fed up knee... it decided to seize up on the last day. But I made it out with a good walking stick, and since it was only a final 3 hour walk, it wasn't too bad.
I'll post up some pictures when I get a chance to sort through them. Most didn't turn out well, since it was overcast for the first, and longest, day. But there's a few that are worth looking at.
And Queenstown is quite nice. We just stopped for lunch on Sunday. Very much the tourist spot. And I could definitely see the attraction for anyone under 30 who is backpacking around... very trendy, party scene.