Any input regarding the riding differences of replacing Progressive front HD springs vs the Progressive Cartridge System? Thinking it would make a nice winter project, just debating which way to go. I noticed in some earlier posts (in 2011) that there were a few issues with the cartridge losing its gas charge, requiring tear-down to replace the defective cartridge. I don't want to have to tear down my bagger if it failed. I have the front Progressive HD springs in my Sportster. It helped a wee bit but nothing to write home about. My Sportster has always been a smooth ride to begin with. My Ultra is also a smooth ride but you don't notice the improvements until you do them.