Yeah, the auto does decent on most images. BUT, as I do a lot of architectural work with tilt/shift lenses and also with large format lenses attached to a 1DsMkIII body, the auto CA has no clue what to do with the images. Most times, it just goes nuts and in order to even get an image that is usable, it's 1) disable the Auto CA or 2) process manually in PSCS5.
I understand that for most people, controlling (or even seeing CA) is very, very hard. BUT, for others, we see it a mile away. LR3 was a great solution, shooting tethered in the field. We usually walk out of the job with all the work done, edited, and "finished" for the client. With LR4, we are having to come back and deliver the work at a later date because LR4 has made it almost impossible to edit in real time.
What would seem to matter is that he said it worked great for him as a professional using tilt shift lenses. Proof is in the pudding. In any case, in practical use, the new CA tool does not work as well as the old one. It's pretty apparent as soon as you start using it.
If you guys have files, which you were able to correct CA in LR3, but not in LR4, you should send them to Adobe (Eric Chan). Otherwise Adobe won`t be able to find a solution. I for one would also like to have those sliders back.