I am ashamed to admit it, but it was 10 months before I started to fool around with the rear shock absorber settings on my K1200RS. I had not been pleased with the performance of the suspension in that it didn't track small road irregularities well at all. The bike simply didn't want to track in a straight line even on newly paved asphalt. There was a certain drama that occurred while in curves. Suffice it to say I figured it had to be possible to achieve a better balance in the suspenders. By the time I thought about doing something & acting on that impulse, 10 months had gone by.
In short, I set the preload at one inch of static sag (with me sitting on the bike). This turns out to be the second position on the preload ramp as per the book (I weigh 195lbs).
Then came the task of setting the damping. Having been spoiled by an Ohlins on my previous K75S, I anticipated that I needed to add rebound damping to the stock Showa on the K12. As I added damping, I noted while sitting on the bike & bouncing up & down that it behaved as if there was no suspension (didn't move). It would handle large bumps all right but had become very harsh otherwise. I suspected that something was different here, as the damping screw didn't seem to affect med/high speed damping but instead affected the low speed circuit.
During a conversation with a technician at Works Performance, I confirmed that adjusting the Showa did indeed affect the low speed performance of the shock & did "nothing" to the medium & high speed rebound damping. I discovered that at one & one-half turns out from being bottomed in (max hard), that the shock had a 1/16th turn change from compliant to harsh. I finally settled on setting the damping adjustment at 2 & 3/4 turns out from maximum hard (bottom-clockwise) essentially removing any additional damping in the low speed circuit.
The personality of the bike took on a whole different demeanor. It will track straight & true on a smooth asphalt surface now. The uneasy drama during curves has disappeared as well. The bike is capable of swallowing up really bumpy roads with ease & doing so comfortably as well.
If you're not satisfied with the handling on your K12, try adjusting the shock as I did. See if it doesn't make as dramatic a difference on your bike as well. It sure beats the price of aftermarket shocks!