as far as someone is concerned
and so far as someone is concernedfrom the point of view of someone. Bob: Isn't this cake good? Alice: Yes, indeed. This is the best cake I have ever eaten as far as I'm concerned. As far as we are concerned, anything at all would be fine for dinner.
as far as something is concerned
and so far as something is concernedhaving to do with something; pertaining to something; as for something. This bill? As far as that's concerned, the committee will have to take care of it. As far as the roof's concerned, it will just have to last another year.