Living here and going thru cat claw a bunch, I can assure you that NONE of the kuiu or Sitka will hold up to continuous cat claw. Best bet is 511 pants or jeans. That cat claw is some nasty stuff. I try to avoid it at all costs, and if I have to go thru it, I just expect my kuiu or sitka pants to have new "runs" in it when I am done. Honestly, I am not usually as worried about my pants as I am my arms. I hate picking thorns out.
If you are set on wearing Kuiu thru it, I have had the best luck with the tetons. I think they are a little stiffer than the attacks.