I have the June Taylor Shape Cutter also. Mine is the smaller 12 inch model - it was on sale at Walmart for $8.00 when they were getting rid of their fabric department years ago. At the time I got it more because of the price and thought it was worth a try, and so happy with it. I have the Accuquilt 1.5 and 2.5 dies for cutting a lot of them. Just checked out the Stripology online and they seem so similar you need to determine what size would best fit your needs.
I would not worry about knicks - unless you are really unsteady - otherwise you are in a fairly narrow slit, not like the edge of a ruler.