Progressive Springs - benefits

[stevewj]

I'm watching these on eBay. What is the benefit of "progressive " springs over stock ? The pidgeon English in the description is of no help ha ha
Do I want these ?

 http://pages.ebay.com/link/?nav=item.view&alt=web&id=390927657316

[ka-ja]

Hi,
     Basically the harder you brake there more spring pressure it creates as the suspension compresses, at normal travel the suspension absorbs shocks as normal, but as the forks compress, the springing helps stop "bottoming. Hagon progressive springs are good at a comparable cost, I fitted them on my 400/4.---Ken
     Example here, higher cost set includes correct oil.
     http://www.hagon-shocks.co.uk/catalog/config.aspx?TypeID=F