Just a note - I don't think manufacturers ever release this type of information, but synthetic leathers generally end up being worse for the environment than animal leather because they require petroleum, vinyl, polyester and/or polyurethane to manufacture. Some of those components don't ever break down in the environment, and the latter three release pretty ugly emissions when they're made.
Farting cows aren't great, but neither is the environmental haul/impact required to create the fake stuff. We had Nuluxe in our IS 350 and I had no qualms about it in that car, but when you keep up with leather, it's nicer long term, IMO. I think Nuluxe is great for most people because it requires 0 upkeep and conditioning, doesn't crack, wrinkles less, etc... but for a car like the IS 500, I wish for a leather option.
Overall, a really small thing and not something that would prevent me from buying it!