One of the great features with more upper-level cameras today is the ability to adjust AF settings for a specific lens. I had tried it a few times in the past with no benefit, so it's been unused for some time. With the Tamron 28-75 I finally found a use for that feature, as it appeared to back focus. Since this is a fast lens at f/2.8 throughout, getting focus right can make a pretty big difference! I dropped in +3 of 'focus compensation' and the results are very impressive, and justify my letting a few primes go for this bulky but talented zoom. I then rechecked the new-to-me 18-135 and decided to give it +2 and results look better there as well.
The Vivitar 2x + macro teleconverter arrived faster than I had expected, and oh my does it get me up close! With the DA40 xs now at 80mm and capable of 1:1 focus (slightly more in fact), this could be worth having around. It's somewhat dense given the lens elements in the TC, and far shots show some definite loss of contrast - but up close it's definitely a great option, one that I think will be used more than close-up filters. I will give them each some camera time and see what I think.