I've just made a small trinket box and polished it with carnauba, using the 'Polishing shop' mop for the bottom, and the 'Chestnut' mop for the lid. The photos really don't do justice to the actual difference in finish; the lid has a much better shine and you will notice that a powdery wax residue has collected in the grooves on the bottom - I later repolished this with the Chestnut mop, which raised the shine and cleaned out the groove.
From the next 2 photos you'll see how much finer the Chestnut mop is...it's on the right....
firstly, the face of the mops...
...and the edges
To be fair to the Polishing Shop, they list in their catalogue a finer mop (WDR Quality) than the one that I bought (G Quality), but it was out of stock at the time that I bought, and is still out of stock. However, their on-line catalogue states that the one that I bought (G Quality) gives a superfine finish!
As for the price, the G Quality (and the WDR, if ever it's in stock) is £5.88 for an 8" x 1" and the Chestnut mop is usually listed at about double that price.
Les