This is my first of the Good Omens scents, so I can't comment on how it compares to Aziraphale, but I thought I'd give reviewing it a go!
In bottle: This smells almost like gin to me, along with tobacco. It has a very boozy scent, but not in a sweet way at all.
Wet: The leather and tobacco are both very prominent, but the scent likes to cling to the skin. It definitely evokes the image of an old leather armchair in someone's study, with years of tobacco smoke clinging to it. It has some of the parchment smell to it too, but never quite ventures into the pencil shavings note that some wood smells can have.
Dry: As it dries, the tobacco mellows and a sort of skin musk smell comes curling out. It stays close to the skin and is unexpected sensual, like the smell of a man right at the collarbone. It's the kind of scent that makes me want to draw closer to inhale it deeply, since it's so subtle and yet so sexy.
Overall, I think this blend manages to capture all the things I was hoping for; parchment, the smell of a library filled with old books, and a hint of sweet tobacco. I think this would be a fantastic scent to wear either by itself, or blended with any number of other scents!