You're not alone, jarinzfin - we'd never flown first class before either! As such, we had a great time and there was quite a sense of occasion. The cabin was ultra-spacious and it was fun to be right up front in the nose of the 747, the staff were extremely attentive, the Dom Perignon flowed liberally, and the food (served from a silver trolley, which makes for an amusing change) was pretty good (SYD-AKL is a breakfast flight, and breakfast aboard a plane is seldom exciting in my experience). Unless you were unlucky with your crew (and I've never had bad service on TG) I think you'd have fun. The cabin is unlikely to be very full on that sector (in our case, only 5/14 seats were occupied) and that adds to the impression of being on your own private jet! How much are the fares ex-NZ, out of curiosity?