We picked this cave instead of the Glowworm cave because you could take photos here. Great choice! The spiral ramp in and out of the cave was remarkable. The cave has many features including a river (you could take the wet tour and go blackwater rafting), stalactites, stalagmites, column, pools, and glow worms - which you could see up close. You could also see the sticky "threads" the glow worms make to catch their prey because they are so close. The whole path is a cemented ramp so it's easy to walk through it. We didn't pre-book and just called the morning of our tour and got a discounted rate; this is probably not advisable during busier tourist seasons. Our guide told us that the carbon monoxide levels are monitored in all the caves there and if it goes over a threshold, the cave could be closed - this happens more with the glowworm cave as many more people go there (there were buses parked there as we went through). So you could potentially go there and not be able to go on the tour!
The tour takes about 2 hours, including the shuttle ride from/to the Legendary Blackwater Rafting Co. where you check in. You could buy food and merchandise and use the toilets here; there are no facilities at the cave itself. The shuttle picks up from the i-site center and the entrance to the glowworm cave as well. This was worth the drive to Waitomo. Highly recommended!