I bought the ACE a while back and naively believed their claim to authenticity. By looking very closely to the originals online, I realized how off the Ace is. Wrong reds and whites, Black line between rows too thin, no stitching visible on the woven side, black underside, Jacquard fabric feels synthetic, etc. etc.
The Dunlop JH01 when AB'd side by side is spectacularly more accurate than the ACE. Colors and exact patterns are spot on. The underside light color is right and shows the four lines of stitching like the original. It seems to be suede leather which feels great and nears the light fawn color of the original. The woven Jacquard side feels like coton (whatever it is) and is very soft. The comfort is unreal for this kind of straps. Very soft.
Modern improvements: Those who complained about the rivets will be happy to know that Dunlop heard your grievances and switched to a sewn leather on the lower bout strap pin. Rivets remain on the upperbout front (horn) for authentic look but the backside are very smooth and won't scratch the guitar.
This strap is only 10€ more than the ACE, the choice is clear. Get this one.
