Yes, there are very distinct machine cutter swirls the entire length of the rib under the firing pin channel of the slide. They are rough enough to feel and make a slight noise as they ride over the top round in a new magazine. The swirls have not caused any issues with my Shield, though I think I'm going to polish them a bit just to smooth slide travel.
I found the .45 Shield to be very quick on target and easy to keep there in rapid shooting. Much easier than I expected.
Looking at mine the other night, after shooting many rounds over the last half of year, it looks like they polish themselves to a degree. Even though they never bothered me to start with, they look to be less noticeable now.