Apparently, the Sorento Auto is a good box, one of the best, so I'm led to believe. Personally I don't have any experience with it, I had the manual, which is more than capable. I would question the fact that you need a manual override for hilly sections, because then an auto isn't really an auto if it's being used manually.
Ok, I'll come clean, I'm not a fan of auto's, you may not be either, so is there any way you could trial one for a while, David?