I believe I found the culprit of the problem I wrote about in
Epson P9000 sharpness/acutance . It's lightroom's "zoom to fill" feature which I believe did not mess up images before. Here is a jpg exported through the "print to file" command out of lightroom with the same settings as the print I'm sending to the printer. Having successfully printed out of photoshop without the sharpness loss I'm close to 100% certain lightroom is at fault here.
I can't confirm Lightroom's internal logic in terms of scaling the image before it's sent to the printer driver, but I believe the Image is being scaled to the resolution requested for the print, then "zoomed to fill" by a few pixels and thus destroying acutance. I'm not sure if at some point this was reversed, where the image was "zoomed to fill" (basically pre cropped), then scaled down and print sharpened. The difference in the resulting print is quite striking when dealing with subtle skin textures or rock textures in landscapes (among many other things). This is especially noticable in smaller prints that are viewed up close by people who still have decent eyesight.
