I agree it's mostly semantics and up to personal interpretation. Personally, I usually think of 7-8 inches as "big", with anything beyond 8 as hung. I do draw some distinction between the words, and my guideline ideas are not static. That's not taking into account the girth, which can change my perception. It also tends to vary for me based on who that dick is attached to. If a buff, hairy, 6'4 guy had an 8 inch dick, it's just not going to appear the same as if that same dick was on a short, petite, skinny twink. And without a measurement, I might think the buff guy has a nice big dick. But I might go "holy shit, look at that cock" when it's on the twink. *Shrug* But yeah, 8 is usually the general "tipping point" in my book.
PS - Your piece is fucking mouthwatering!