Sunrise Safari is AKL CL only; Wanyama (Sunset) Safari and Night Vision Safari are any AKL guests, not just CL.
We did all three of them in April. The Night Vision was pretty new - I think it started last fall - so I didn't have much info before we signed up for it. It was fun, though. You go to two savannas in a jeep - you ride along the edge of the smaller Kidani savanna (Pembe?), and then enter and ride through the Sunset Savanna. The animals can come right up close to you on the Sunset Savanna - we were about 2 inches from a giraffe at one point.

You also get some Night Vision Safari-only souveniers, like a glow in the dark pin (same conservation fund pin as the other tours, but this one glows) and a glow in the dark bracelet.
I've been meaning to write a review comparing all 3, but haven't gotten off my lazy butt to do it yet.

Hopefully I'll have a chance soon.