I installed the Progressive front lowering springs along with a PCS Slam about 3 weeks ago. After riding it quite a bit, I became frustrated with the peg scraping and occasional pipe drag. The bike seemed to absorb small bumps better and I really like the "long and low" look as opposed to the raked look, but I missed diving into turns with confidence. It actually took me awhile to become accustomed to the peg scraping and caught myself jerking my foot off the peg the first few times it happened. It did occur to me that the scrapes were not an indication that I was running out of tire or about to exceed the max lean angle, but that they were simply closer to the ground. Even still, my subconscious equates the sound of grinding metal to impending doom.
Fast forward to today...I pulled the Progressives and reinstalled the factory springs. Did about 40 miles with a combination of curvy backroads (plenty of 15 mph posted turns) and highway. I only scraped once on the backroads and ran the length mostly in 3rd gear without bogging. Freeway speeds varied up to about 90 when traffic permitted. When I got home I immediately put the Progressives back in.
The difference in shock absorption is night and day. I didn't really notice it when I first installed the Progressives, but comparing the two in a single day has convinced me that they are definitely an improvment over stock. The factory springs just felt rigid and unforgiving...maybe unrefined is the word. I also feel more connected to the road with the Progressives, whereas the factory parts make the front end feel light and disconnected with a bit more wander at highway speeds.
I realize that Progressive/PCS sell stock length progressives, and that may be an option for me later on, but for now I think I'll focus on embracing the peg scrapes. Just thought I'd share if anyone was on the fence.