very nice image. And yes maybe the 10 min cause distortion of the shape of stars. The galaxy is very sharp, with many details and good color. Beautiful photo !
note: perhaps there are more 5 or 6 faint galaxies. I think it worths try with 30 up to 100 3 min subs. You can adjust the position of galaxy manually (manual guiding). If they are near, the DSS will stack them. And the displacement will reduce the noise.
Maybe with less ISO to don't saturate the stars, that make all them white.