We found the guide quite rude at the beginning though she did improve in the course of the tour.
You meet the guide at the reserve near the entrance to the cave. The guide collected our tickets then took off up the path at a very fast pace. The path is steep and then you reach some flights of stairs. The guide waited inside the cave and when the first of the tour group arrived said in a very smug gloating sort of way.. "noone told you about the stairs did they." ..and no they didn't. But they really should. There are well over two hundred stairs in the tour of this cave, which in caving terms is not bad, but people should be aware when they pay their money, and the guides should say something about it when the group meets up. If there's nowhere suitable to stop on the way up so people can catch up, then they could at least say they'll be waiting up inside the cave where there will be time to catch your breath.
The Aranui cave has the most crystal formations of the display caves at Waitomo. Unfortunatley quite a lot of the stalactites have been broken in earlier times when people would take them as souvenirs. There are no shawls to speak of in the Aranui Cave. Ruakuri cave has some nice shawls if you want to see that. We enjoyed the Aranui cave but we do enjoy visiting caves generally.
The big hit for us in this cave was the colony of cave weta. Now that was cool!
If you have been to Jenolan Caves near Sydney Australia, or are moving on to Sydney and the Blue Mountains as part of your trip, then you might find it useful to know that the Aranui Cave is nowhere near as spectacular as the better caves at Jenolan if you are looking for crystal formations.