Harmy said:
@Turisu: Actually, the sharpening isn't from the downscale script but rather from the upscaling. Here's a simple bicubic upscale in PS. There is some detail loss off course but it's super minor.
I think the standard bicubic upscale looks markedly better than the image you generated using the script. Whatever was causing his tan shirt collar to look unnaturally jagged is gone now.