I have been doing a lot of thinking on this lately actually... I may switch up my setup.. when you talk shocks you really need to understand the difference between the three main valving schemes and which one fits with your needs/wants.
Digressive - small bumps are firm, large bumps at speed feel comparatively softer.. what this means is driving down the road you feel all the pavement inconstancies and bumps quite a lot. Aluminum bodied vehicles tend to amplify this too. The result is a tight/firm but rattly feel. ( great for high speed pre-runner type driving, also provides a nice tight highway feel, not so much for daily city driving.
Linear - just like it sounds, shocks react in a linear manner as a function of force and compression length
Progressive - Factory shocks are progressive, small bumps and pavement imperfections are soaked up by the shock removing vibration and "rattle" but the tradeoff is a squishy feel. not the best for load control during towing.
all Bilstein shocks are all digressive.
I do a lot of city driving, I have learned I prefer Progressive and as such I am planning on replacing them. my search is on for a premium quality progressive lift setup. I get my bonus next week and may look at swapping out.
looking at the chart above, most DD bumps happen in and around 2 in/sec. If we use this value you can see the vast difference in force required to compress the shock.. and since every action has an equal and opposite reaction and this force if not absorbed by the shock is transmitted into the vehicle chassis..
@ 2 in/sec
Digressive = ~475 lbs
Linear = ~125 lbs
Progressive = ~ ~50-75 lbs
hope this helps everyone pick the the system which best meets their needs..