I generally like the firmer dampening of the HDs, but yes, there are certain road conditions where they do provide a bit of a harsh ride. Very well controlled, but harsh. Sometimes that level of control makes bigger dips less punishing than softer setups, though. Definitely a trade off.
I never liked FSDs. They don't seem to hold up as well for as long and they always feel just mushy to me.
I have loved every set of adjustable Konis I've ever installed for both myself and customers, whether it be Reds or the Sport Yellows. I tend to put them right in the middle of their adjustment range with stock springs, usually ever so slightly on the firm side of the middle to be accurate, and they have always provided an excellent, well-controlled ride and take a bit of the harsh edge off the ride compared to HDs.
The first set of Reds I ever installed I did what Koni said and set them fully soft. After about 2 weeks it felt like I was driving on 4 bad struts. It was pretty bad. And unfortunately with the reds, you have to remove them to adjust. I eventually did so, put them in the middle and was happy with them ever since. I think I recall the adjustment full soft to full firm was somewhere just shy of 2 and 1/4 turn. I'd turn it to the full firm setting, then back it off one full turn. Have been happy with that setting on every car I've used it on, but then again, I don't mind HDs in most situations... But even at that relatively firm setting, they're a bit more forgiving than HDs.
What I can say about HDs is they seem to last. They do indeed take quite a lot of punishment and never seem the worse for wear even after 150k miles. Most OE dampers are getting mushy by 50k...