I've never played a Koa bird, but I have a Lion and the newer Black Whale and recently sold my wife's Moon bird tenor (which was replaced with a Hummingbird concert), so I've played quite a few of the aNueNue models.
As I've commented elsewhere, the Lion's color is not for everyone. Depending on the light, there are flecks under the gloss that will sparkle but they are generally not obvious when just hanging in my room under regular light. In terms of sound, I preferred the Lion to the Moon bird, which is why the Moon bird was the odd man out. Like Contrails said, the Lion is not as bright/punchy, but I prefer the well-rounded sound of the cedar/koa combo. I posted on the slight neck differences here:
NUD: Anuenue LOUT Lion. My wife did a comparison of the Moon bird to Lion here, although I don't think the Lion's sound is completely accurate b/c she struggled to hold it without a strap while her Moon bird had one:
Lion vs Moon bird
The Black Whale was a recent addition, and I owe the forum a NUD but haven't had the chance to play it enough. I will say that the whales on the fretboard throw me off slightly b/c they start at the 3rd fret and go to the 5th but the bulk of the body is in the 4th. There are side dots, but when moving back quickly from higher frets, I find myself sometimes on 4 instead of what I meant to go to b/c of the visual cue of the whale body. That's more on me than an indictment of the uke, but if you bounce between different ukes alot it can be an adjustment. Soundwise, it's a tougher comparison between the Lion and the Whale. In addition to having them strung differently right now (Lion is currently low G for an arrangement I'm working on), they sound somewhat similar to me. Perhaps a little more overtones and sound coming from the Whale, likely b/c its wood is stiffer (both have Uke Logic soft tension for A-C), but I need to play them both more.
Overall, I think the feel and sound of the Lion is better than more expensive ukes I own, and I always recommend it if a person can get past the color.