There are some beautiful star fields in that image, especially the ones with the bright stars near the outer reaches of the galaxy. There are also quite a few nice looking background galaxies scattered throughout. I bet it took me a good 20 minutes to just casually sweep back and forth across the image to take in the whole thing.

I am curious though about the arcing bands that are blurry looking. At first I thought they might just be foreground dust/gas but they don't match up at all with the spiral arms of the galaxy. There is no explanation of them in the description of the images. The blurriness around the fringes of the image are explained as Earth-based images of M101 and its surrounding sky upon which the Hubble images where laid. But no comments on the blurry arcs.