I have Ikon shocks on both my CB750.
Ikon with progressive springs on my K6, non progressive on my K2.
Both bikes have progressive springs in the fork, Wirth vs Progressive. They look very similar side by side.
Progressive shock model my K6 has much better. Very comfortable and has good handling at the same time.
Purchased from Classic Cycle City Germany (eBay). Chromed version with caps, almost CB750 stock look.
My K2's are either too soft or too hard. I have tried all combinations with spring setting and dampening.
Since it is stock and my wife's favourite it has the soft setting. This model also chromed with caps.
I recommend the progressive version, huge difference.