Not sure if this properly answers your question Dave, but I couldn't speak highly enough for the 70-200mm f/4L IS. The copy I used to own was spot on.

Here's three photos, the first at very close to MFD and the second two with extension tubes (36mm I think). I can't really see anything to complain about in any of them (IQ wise anyway).


Flutterby by Ben__Taylor, on Flickr



Yellow and blue collision by Ben__Taylor, on Flickr


Palm pilot by Ben__Taylor, on Flickr