I mounted each lens on one of our Sony A77s with exactly the same settings and as usual took the exact same shots without moving my feet at all. I shot at 28MM, 50MM, 85MM, 100MM, and 135MM. I took 20 identical shots with each camera and went inside and downloaded them. I was already impressed at the speed of the auto focus with the 18-135 and also that it was able to focus on a couple of low contrast shots that the 28-135 struggled with. I put the photos from each in separate folders then opened them side by side for comparison.
The photos were so surprisingly close in sharpness and color quality that rather than making a decision I waited until my wife came home to see if she agreed with my thinking. I showed her the photos 1 at a time side by side and had her pick the winner. I made a little chart and by the time we had gone through the 20 photos she had picked the Minolta 12 times and the Sony 8 times. Then I had one of our top photographers over and he picked the Sony 7 times, the Minolta 7 times, and 6 ties.
I still feel that the Minolta yields slightly better photos over-all but not by enough to sacrifice the extra benefits of the modern day Sony features:
Normally I would post photo comparisons but there is really no point in posting the side by side photos I took because they are honestly so close in sharpness and color that they would look identical when re-sized for the web!
I kinda wonder if some of the same Minolta team that designed the 28-135 helped with the Sony 18-135?
We've now shot 2 weddings with the new 18-135 and we don't miss the 28-135 at all. The 18-135 has much better communication with the camera for indoor flash shoots and focuses much faster in low light.
We've now taken tens of thousands of concert and wedding photos. For outdoor shots or with flash indoors this lens is fantastic. It has become my wife's favorite lens! The only thing that could have made this lens better for our purposes is if it was a 2.8 through the range so we could shoot indoor concerts with no flash. For that we use the Sony 16-50 2.8 lens. If you like classic rock check out our excellent photos on the RLC pages and the pages under the Band photography tab.