Chiming in with another vote to skip it at dark. It's a bust. Their attempt to add lighting is a fail, as much as it pains me to say. The simulated sunset lighting it just awful, it's too bright and harsh and casts so many shadows it ruins the effect. Overall it's too dark to see any animals. Most you can see is a blob of a shape off in the distance if you squint just so
The route changes and you cut off the good view of the elephants.
There is a nice area where they have a simulated moonlight that I rather enjoy but by no means is it enough to say the ride is worth going.
Dusk is very nice for sure, though no better than any other daytime ride.
They have modified their animal activities so that the animals are moving around all day so really, anytime can be a good time to go. You never know when you'll encounter a truck out putting out feed or a keeper calling in a group of animals or releasing another group.