I can absolutely feel the difference between soft, normal and hard settings on my GS. I set it up and adjust it the exact same as 58058D - 1 helmet + luggage. I leave it at this setting but change between soft, normal, and hard all the time depending on the road and how I'm riding.
I eventually upgraded to Ohlins on all my sport bikes and my dedicated track bike. Yes, the suspension performance was great especially after riding 2 years on the stock GSXR 750 (track bike) and then upgrading to Ohlins front and rear. But the springs were dialed in for my weight, fine tuned for high/low speed rebound and compression damping, and road use or track use.
With the GS, my load changes from full packed luggage to the weight of running a few errands around town to me solo riding. While the suspension is probably not perfect in every condition, it certainly works great across the entire usage profile. I'm very pleased with BMW's suspension and love the on-the-fly adjustability.
I eventually upgraded to Ohlins on all my sport bikes and my dedicated track bike. Yes, the suspension performance was great especially after riding 2 years on the stock GSXR 750 (track bike) and then upgrading to Ohlins front and rear. But the springs were dialed in for my weight, fine tuned for high/low speed rebound and compression damping, and road use or track use.
With the GS, my load changes from full packed luggage to the weight of running a few errands around town to me solo riding. While the suspension is probably not perfect in every condition, it certainly works great across the entire usage profile. I'm very pleased with BMW's suspension and love the on-the-fly adjustability.
For me, on the K1300S, I would set the spring at One helmet + Luggage for my solo riding, with no luggage weight. Depending on the road I was on for my commute, I toggled between all three damping settings. For the rough sections I was in either soft or normal if I felt like a spirited ride. For smooth roads in the twisties, definitely I was in Sport mode. Sport mode for Track use. Freeways, normal or soft depending on the quality of the road again. Riding two up, with no luggage, I used the 2 helmets + Luggage, never road 2 up with luggage, so I did not need the extra spring on that. The spring provides the support neccesary for the forces the bike (and you) are experiencing, the damping adjustments determine how rapidly the shock is allowed to react to an impact/bump, etc.
On the K1300S, there was a significant difference in all these settings. Are they superior to aftermarket dialed in properly? Absolutely NOT. However, for me, they were very 'reasonable' settings and I was able to work with them. They were Very convenient. That is the real key, convenient.
YMMV