My new lens arrived today and I did a few test shots.
The two images are 100% crops a few minutes apart, and although the exposure is a little different the improvement when manually overriding AF is clear.
I'll be setting some time aside after Christmas to calibrate the AF on my lenses, and have been doing some reading.
The internet is full of sometimes conflicting opinions so I will be interested in some experiences of people here on the best approach.
The slightly darker image was with manual adjustment.
DSC_2493_0045 by randaldinga, on Flickr
DSC_2488 copy_0042 by randaldinga, on Flickr