Dave, I see you used to have an 09 FLTRSE3, so I am going to pick your brain on the suspension. I still have the stock front suspension but have changed out the rear air shocks for the HD hand adjustable ones. I ride 2-up mostly 95% of the time and only 1-up back and forth to work, 30 miles round trip. Our combined weight is 400# along with a chopped tour pak, I have tried going back and forth on the rear shocks to get the best ride w/o bottoming out. If I set it to not bottom out but to carry us it is stiff as a board, and if I go the other way then holes, bumps it will bottom out. I also do not like the effect the front suspension does, it seems to just shake the front end if I hit a large bump, hole, etc., like something is loose.
I have been looking at the Progressive monotubes for my bike, from what I have read they seem to help and now I am looking at different rear shocks. So far all I have gotten is info from Super Shox......I don't want to invest a chit load of $$ as I will probably trade in 2 years or less but I want a smoother ride, for my wife especially and myself. Thanks
Like you, I first installed the HD Premium Adjustable Shocks on the rear of the '09 SERG,,, 'Noticed an improvement, but nothing earth shattering... Then installed the HD Premium Front Cartridges,,, Transformed the whole Bike! Excellent Ride Quality, Great Handling, Minimal Brake Dive for 50k mi. so far

On the '09 SERG, the front end is the real culprit, mushy, poor damping...
Instead of jumping from shock to shock, install the HD Premium Cartridges, give it 700 mi. or so to allow the front to settle in, play with the rear adjustment to make sure it's in the sweet spot, and enjoy the Ride...
JMHO,,, Your results may vary...
For any good suspension, the front & rear must play well together...