new 70-300L - am I nuts?

[Sheiky]

A simple check to see if you need AF-micro adjustment is to take identical shots, one with AF and one MF with live view at 10x. If the results are really different, you could do AFMA. It's very easy, even a DIY solution works pretty well.
However picture 4 looks to be pretty well focused to me.

As far as the images, Brant and I both guesed wrong haha However there are a few things you should take notice on. You compare two completely different lenses. Perhaps you have shot on the same focal length. I guess you did. On one lens it's on the long end and on the other it's on the wide end of the lens. Zooms don't deliver the same IQ on the whole range so you might as well have had bad luck with the focal length. Testing where the differences are small. AKA you might have hit the sweet spot on the 18-135 and the weak spot on the 70-300L at the same time