I agree with both of you. We have done the auto tipping once. We really didn't notice much difference in our treatment, until we went the next year without auto tipping. That's when we said "They are much more attentive to our needs than last year". Possibly, we just had a better staff but I really don't think so. The only person who really "tried" to make a difference when we auto tipped was our head waiter. He went out of his way to please us and because of that we gave him extra at the end of our trip. He actually told me to put the money back that it was not neccessary. I insisted and he gave me a big hug and a very warm thank you.
Unfortunately, there are some people who would not tip if it wasn't added to their bill. That is why (In my opinion) many cruise lines are going to this type of requirement.