Gave Nik Sharpener Pro 2 a try some time ago and found its sharpening very aggressive. When applying the filter(s) the luminosity histogram just jumps to the right.
I haven't tested it on paper though and know that the ultimate proof is in the pudding/print, BUT:
I have however extensively tested PK Sharpener on a D-lab printer. I've sent numerous pictures to a lab with different sharpening settings.
My conclusion was that anything BEYOND PK Sharpener setting is TOO sharp (I've printed images with sharpening settings beyond PK Sharpener). It just doesn't look natural anymore. Nik Sharpener Pro goes way beyond PK Sharpener setting.
What bothers me is the difference in sharpening between Photokit and Nik. Nik is so much more aggressive. How is it possible that those 2 pieces of software, both created for media specific sharpening, behave so differently. I mean both companies probably used a lot of real world data to set their sharpening parameters and yet there's such a difference.
Most of the time I use Uwe's Steinmueller's (www.outbackphoto.com
) EasyS sharpening, but as a target point I use Photokit Sharpener.
I set the media specific sharpening in Photokit and try to get the same sharpeness in EasyS by changing the layer's opacity.