I just updeated ACR to ver. 188.8.131.529 in my CS5, to be able to work with my Canon 1Dx files.
I see a change to use lens profiles, but when I open the tab for manual correction, trying to adjust chromatic abberation, I have no sliders available when I check either highlight edges or all edges. From what I could determine on Adobe community forum, these should be present.
Am I missing something obvious?