I heard it was related to better handling , who knows MOCO reason other than a reason to bump the price

16 SG. Replaced the enforcer combos 19/16 with a set of talons off the SGS 19/18. Dont care about cushy. I prefer a more taught ride personally. Though I can guarantee Im not the typical HD guy. And have built both my LRS and bagger with all around performance in mind. I can tell you handling improved. Got rid of alot of the side jiggly, wandering and unplanted feel at speed in turns. Especially if bumps or dips are thrown in. Ive also done the sta bo swingarm bearings and suspension is dialed. But those were done before the wheels swap. So you can take it from a guy who made the swap on the same bike over the ramblings its all for HD sales, blah, blah (for wheels hidden by bags.... smh)....

The 18" tire allows more of the new talon wheel to be seen. My last bike had 16" and my current bike has 18" and I can't say my current bike rides harsher.The 19 and 18" wheels gives the specials a custom look from the factory, esp with the talon wheels.

Yes, you can see more of the rear wheel, and matches the general style better.
Bottonline is just for looks at the cost of comfort.
Also you can see that clean the rear wheel an ordeal...

With sh4325's avatar, you definitely would be 'stiffer'