Scanning into Photoshop

[jdavis3]

I just purchased a G6020 Mega Tank printer and tried scanning a photo directly into photoshop at 600 dpi. The quality was so terrible that I could not use it. When I use the scan utility from Canon, the scan is excellent. Why is there a huge difference when I scan directly into Photoshop?
I tried scanning the same image with my Brother laserjet MFC directly into Photoshop and it was perfect. See examples. Both images were reduced from the original scan of 600DPI to 96DPI for upload purposes.

Brother Scan reduced from 600dpi to 96 dpiCanon G6020 scan, same parameters