Well the less flexible cable seems more cheaply made. I'm concerned constant flexing might break it. Also these things need to be stuffed inside a small box with a lot of other wires. If the cable is more flexible it makes it easier for the end user to install. Not a big thing but I know I'd want more flexible cable if I was given the option.
As for the sharpie, it would look unprofessional. You might not be able to see it once it's installed but my customers would see it when they go to install it.
Basically I'm just trying to deliver the best and most professional product I can within my budget.