I had the pleasure of obtaining a used pair of Progressive 440 shocks, they were one year old and some slight rusting on the springs. The previous owner had them replaced under warranty due to the rusting. I tried them on my bike and I must say the difference was amazing. Sadly one of the shocks blew a seal 80 miles later and now I have put the original boingy bits back on. My concern before I blow over £400 on a new set surrounds the quality of the 440's. Do they all rust? Are they programmed to self destruct one week out of warranty? I am told they can not be rebuilt. Luckily the guy I brought them off is a top bloke and has given me a full refund.