| Bungi,
I have a set of Hyperpro springs in my garage...you can have them for nowt!
I fitted them some years back and found they were "OK" for road riding, but then did a TD at Brands....I HATED THEM! The reason was (as Kev[skidlids] implied also), the feel during braking was inconsistent.
Using linear rate springs, the amount of travel is directly proportional to the load applied i.e. the harder the braking the more travel.
However, with progressive springs, the travel is not directly proportional to load. Therefore, for different corner entry speed/braking force, the amount of travel was not predictable.
I dunno, but when I am braking from 100+ into Paddock Hill, I EXPECT a certain amount of dive..in fact this can be used to one's advantage (or opposite!) to reduce trail and increase steering response.
Now I'm waffling.
If you want them..come n' get 'em! | 
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