FX Superior vs regular STX cleaning

Has anyone else noticed how much cleaner the Superior liners stay compared to the older regular STX liners?

With the older STX liners, after 300 to 1500 shots(depending on ammo and liner length), I would see accuracy drop offs(wider groups/more and wilder flyers). With a 600mm or 700mm liner, it would take at LEAST 12 pull-thrus with patchworm(1 ballistol patch, followed by 10+ felt button/ballistol patches, followed by 2 dry patches) to get it clean! 

With the new Superior liners, I have let them go over 2500 shots(slugs and/or pellets) before seeing any accuracy difference. And when I clean 380mm, 600mm or 700mm liners, it only take 4 or 5 pull-thrus with same patchworm(1 ballistol patch, then 2 to 3 felt button/ballistol patches, followed by 1 dry patch) to get clean patch pull-thus. Perhap they are polished? The shrouds and LCDs still get filthy and need to be cleaned with the same frequency, however.

Also, I go back and forth from shooting pellets to shooting slugs much easier and quicker(not as many pellets/slugs to "season" the liner to the new ammo).