Just took the one year old progressive 412's off due to slight leak and reinstalled the stock shocks. Put a little over 900 miles on in two weeks and discovered The Progressives are not going back on. YMMV
On my VT1100C I didn't get 3 mos. on my 412's before they leaked. They were also too harsh regardless the settings or load. I really like the stock Showa's on the Valk with aftermarket neoprene bushings so much so I'd like to purchase a used low mileage set for the future change.