We had a very knowledgeable tour guide who spoke at length about the various cave formations as well as the cave's history. The cave itself is rather large. The walkways are well maintained and well lit. It was heartbreaking to see the various stalagmites and stalactites that had been broken by explorers from the past before conservation efforts could be made.
From what we saw from our visit, the earliest tour and the last tour seemed the least crowded. Our tour was at max capacity (they broke us up into two groups to better handle the size) at 2:30pm. This was a problem mainly because the tour groups were so close together that the guides were talking over each other, making it difficult to hear our own tour guide. If Crystal Cave can space the tours a few more minutes apart to avoid this problem, that would definitely help to create a better experience. Our group was also packed with many very unhappy small children. I love the fact that parents are trying to have the children experience something natural and educational, but a dark cave can be very upsetting to some small children. The children in our group loudly screamed their displeasure through the *entire* tour which made it even more difficult to hear the guide (screaming toddlers are loud enough - now imagine several of them screaming at top volume, all at once, amplified in a cave... yikes!). It is a shame because I'm sure many children are well behaved and will love this cave. We just had the "past their nap time" group.
Worth a visit if you're in the area and are interested in learning more about cave formations. If you don't like crowds, then off season may be best.