PC-E NIKKOR 24mm f/3.5D ED - test and results

I've had a love hate relationship with this lens since the day I got it 4 years ago. Its been back to Nikon twice, once because it seized up and the second time to recalibrate. It was giving results where the edges were sharp
the horizon was sharp but the centre middle distance were often soft. Which made it for me unpredictable and highly frustrating. Anyway Nikon offered to sort it out as it may have been reassembled incorrectly. One of the issues with this lens is field curvature which can make focusing a real challenge, a hair turn either way can make a difference.
The cropped images are from jpegs straight out the camera unsharpened.

IMAGE 1. Tresco 1/100 sec at f9 - shift raised - trees without converging verticals

Centre left - slightly soft towards the horizon

Just to the right of the last crop, looks better

Top right edge - good

Lower centre - acceptable

Lower left - pretty good

IMAGE 2. Mapperton 1/6 sec at f10 - shift tilt neutral

Top of door frame on right - very good

Above far door frame - good

Left of centre - very good

image 3. Thailand Garden 1/320 sec at f7.1 - neutral positions

Centre left - not good

Dead centre - excellent

Lower centre - good

High centre to distant trees - excellent

Centre right - terrible

So the results are a bit of a mixed bag which is a shame because at its best its brilliant. In the last shot the lens sings in the centre but the edges scream. Is this out of focus due to field curvature and a more limited depth of field? If I'd used a smaller aperture or tried refocusing would the results have been better... probably. But you would think with a 24mm lens focusing and depth of field would never be an issue.
The first 2 images would make perfectly good prints to at least 18 x 12 the last image would show its weakness at 10 x 8.