I have done this tour in November 2011.
Expect to make lots of friends, do some exciting activities, some awesome tour guides that make certain you have a ton of fun. B-)
The scenery is beautiful, Milford Sound is awesome, my only regret is I should have invested in a good DSLR camera to capture these awesome scenery especially on the South Island. I’m actually going back in Feb so Im not sure if I will meet you, Im not doing the grand kiwi, but I’m doing the Southern Explorer (I unfortunately can only get a week or so off work, so I cant do the whole trip :()
Also make certain you do the Luge in either Queenstown or Rotorua, it is awesome fun! ;D