Thoughts on this, lens owners out there? I have yet to get a normal zoom for my 6D due to dithering about "which one". I would like to have decent performance at minimum focus distance for a walkaround zoom. I hear such good things about the f/2.8 II, but have seen one review stating that performance is so-so at close range. I wonder if I would be happier with the less stellar 24-70 f/4 IS with the close-to-macro performance or with the Sigma or Canon 24-105s or with a good copy of the Tamron f/2.8.