I did have my front forks modified by maxton, they had new springs wound and manufactured new internals with damping in each leg, unlike the standard setup. Cost was about £250 but well worth it as it gives a very nice ride even when the Acerbis 43L tank is full. Much, much better than my friends otherwise identical bike.
Only downsides so far is that the springs rattle a bit in the stanchions if extended over bumps (they told me this would happen) and that I can get some patter over ripples during full on braking. Maxton told me to add some more fork oil to stop it hitting the bump stops to cure this, but I haven't bothered yet 1 year later on, so it's obviously not that bad.
Basically this and the WP shock have transformed the bike enough to panic a few sports bikes at least in slow twisty bits.
Other good stuff:
Lowered touratech foot pegs are more comfortable for long legs.
'Flip a lever' cruise control, side stand fixer and fat foot from http://www.schneidersinc.com/
I also plan to get one of the modified K series brake calipers which motobins supply as I believe this improves the noticably absent OEM braking.
My god, I'm a real anorak!