I put a Wilbers 630 shock on the back of my K75S and it made a huge difference over the stock shock. I was originally going to go with either a YSS or a Works, but what I didn't know was the Wilbers wasn't that much more money than the Works. I paid $550 for my Wilbers 630 built to my specs back in December, plus the 5-year warranty gives me some piece of mind. You could also go with the Wilbers Eco-line for ~$400 and not have the rebound adjustment. Just my $.02.