I've just had them fitted (by a garage, not me) but have only ridden from the garage to home, about 25 miles of wet, greasy roads. Since then it's been solid sub zero temperatures, so I've not been able to give them a try.
Didn't Juggernaut have a set of tools for hire to help with changing springs?
I have had mine in for awhile now and like them. I was going to install them myself but the shop I use said they would install for $60 so I let them do the work.
Had my front Progressives about a year now..shop installed $40..nice improvement over stock...less dive when braking and seems to handle a little better in turns...as my riding skill level improves this evaluation could change...but it is a very affordable upgrade.