I swapped out my rear shock and front springs for a wilbers kit. I am loaded down at 205 lbs, perhaps 220lb dressed, along with HT pannies and the usual farkles and protection plates and bars.
The rear shock has a remote adjustable resvoir which helps on the fly. I have had the set up since late fall of 06. I did the rear for touring, so its set up for 2 up along with a weeks worth of gear, tent, rain gear, and such.
I did the front because I got tied of the clunk up front, and the unusual amount of dive under extreme braking.
Tractability has increased in tight woods and steep dirt grades, front dive is all but gone, but still just enough to give you some sense of progressive windings and softness up top, just not nearly as pronounced as stock. I have it dialed in now and broken in, so I do not get any wollowing like I used to when I was loaded down at speed. Unloaded, I can dive into hard turns under braking, point it and go.
Overall, I would say it really depends on your style of riding, bone stock, back and forth from work, I would have kept it stock. Off road, long hauls, loaded down and 2 up over uneven pavement and dirt roads, I would say it may be worth the cost. I think the front end at the very least is worth the money for upgrades...springs and oil. Its the cheaper of the two, and IMHO, the worst of the two ends form the showroom. Just take your time, look at all your options, and get the right springs for yur style of riding, believe me, you will not regret it.
Typically, the spring dealer should ask you some very specific questions, such as:
1: Your weight
2: Bike weight
3: type of riding, ie..Sport, touring, adventure, high speed, cruising.
4: Do you ride 2 up? IF so how often, 20% 50% or 80% of the time?
You get the picture, after this he will suggest the spring rate, then you can fine tune it after break in by varing oil weights and levels.
"Pain is weakness leaving the body"
"Nothings possible until its done!"
"If ya can't afford the fine, take the lead!"