Just want to put my 2 cents on it... (Hopefully that will not stir up a hornet's nest :fxd:... again...)
Just to note: I have no experience with the H3 steering rack issue and my knowledge is based on my previous mechanical experience.
I see 2 reasons to keep the rack floating. First, as mentioned above, is to reduce the "jaring caused by bumbs in the road" or "isolate the soccer moms delicate hands from feeling vibration through the steering wheel".
The second one is that (and I don't see anyone talking about) is to reduce the fatigue on the internal steering rack components. I've replaced several racks (not on H3) that where destroyed on inside. If the rack is clamped solid then all of road noise fatigue will go directly inside of the steering rack components, resulting in reduced life of the rack.
There is a reason why shock absorbers are created. The worst enemy of ALL OF THE mechanical part is the constant vibration, and that is exactly why all cars (including all of the high-performance sport cars) have suspension and steering shocks and bushings.
Think of it this way: The softer the absorption - the more softer and comfortable and more reliable it gets. The harder the absorption - the more responsive and less reliable it gets... And when someone designing a car they have to balance between this 2... AND, the BALANCE is the key, not all the way one or other. If too soft - it will become like a boat in storm and will make you sick(not comfortable), and if to hard - it will bump like crazy and you will lose all control (not responsive) on high speed or bumpy road(plus you will loose all of your screws in you car and in your brain)
I worked on few race cars for endurance races, and yes, stiff steering rack will give you more feel of the tarmac, but you have to be NUTS not to have any absorption at all. It will not only destroy the the rack very quickly, but also destroy your hands and you will not be able to hold on to steering wheel after several hours.
Then again, I'm talking about race car and not the Hummer. You don't go as fast and large tires do provide some absorption. I guess only time will tell what design was able to balance it out better.
