I've heard it said that for every year sober you gain 1 second of response time to think, before you say or do something stupid upon being provoked.
I've heard liver function should heal normally in about a year. Brain function improves immediately. Not sure if this is fact.
I can say that the physical healing I have seen is pretty remarkable. In 26 years I have never known a sober alkie who died from something related to past alcohol damage. Known a few who bleed from all parts of the body, and they seem to be fine today.
I do know one person who still has hepitis liver damage that still exsists, must have been in a very late stage when he got sober.