I think the common denominator here is that both guys with 9C1's might find the 1104/0929 shocks objectionable as far as ride, especially if they are no longer running the stock size tires. I did note that one is now using SS rear springs, so that should lessen the harshness, as the SS springs are the "softest" on the list of GM replacement springs. I am not sure how much difference there is in the rear spring rate on the 9C1 vs the Fleetwood, but the combination of more weight, (probably) lower spring rate, and control arm bushing differences probably help the Caddy feel less harsh with the same shocks, at least in the back.
I would suggest that the 9C1 guys might give the stock Impala SS shocks a try--something in between the "stiff" and "soft" Bilsteins. Too bad they cost a bit more new, but they are good shocks.
I will say that I've had Edelbrock shocks on my car for the past 2 years, and they have held up so far. It took 2 tries on the rear --they acknowledged having a seal problem early on, but that is all in the past, I am confident.
The other thing I will suggest is to make your decision about shocks with the car adjusted to a condition that was equivalent to what the manufacturer did to make the shock selection/tuning, then figure out where you want to go, or what happened when you made a change that would affect the ride. An example of this is tire pressure, which will affect ride quality considerably--you should adjust the pressure to what is on the label on the door and see if that makes the car feel better or worse. I suspect most of us run more pressure in our tires for daily operation on the basis of "more is better", for better fuel mileage (always an issue, especially with these cars) or some other perceived advantage it may give. The factory selects the tire pressure range with many considerations in mind, and ride quality is right at the top of the list.
