You know those points in time where you're deciding whether to go heli-hiking on the upper glacier or saving $150 and just doing an all day hike on the lower glacier?
I'm sure you do, happens to most of us every day.
When last faced with this dilemma (15 years ago when cycling around South Island) I opted for the heli-hike. and it was brilliant.
This time we opted for the all day hike on the lower glacier figuring it was half the price, it was something I hadn't done and because it had been recommended to us by one of the guys we met on the Milford Sound Track ...
Don't get me wrong, it was nice and everything, but with a rapidly retreating glacier there wasn't really any of the the caves and other features I got to see on the upper glacier, so yea, tip for the future if you're ever this way and making that decision ... if you've got it, spend the money and go heli-hiking.
Oh, and definitely do not waste your money doing the half day hike ... you spend an hour walking to the glacier, another hour walking up and down a short staircase cut into the ice and then you walk out again.
We at least did the full day hike which got us a bit further up the glacier.