Aniline leather is simply dyed with pigment added for consistency in color, and shows imperfections in the hide, will fade out eventually in the sun, and wears fairly easily - not a good leather for cars, to say the least.
Semi-aniline leather is very lightly clearcoated, and is typically softer than typical coated leather. It is subject to wear quicker and easier than coasted leather.
Protected aniline leather (what most of us actually have in cars) are clearcoated, and are the best for wear, color consistency, etc.
The LS and GS460 has the better Semi-aniline leather.
I don't know about the ES.
Somehow the IS with ventilated seats has the Semi-aniline leather.
http://www.clublexus.com/forums/showpost.p...p;postcount=101
Maybe Semi-aniline leather is standard with ventilated seats. :(