I'd replaced my old rear dampers a while ago with Koni Special Actives (along with the other ancillary bits e.g. mounts, reinforcement plates), but hadn't gotten around to the front dampers. Finally got those in last week. Everything in each strut assembly is new aside from springs and upper spring perches. I went for the E36 M3 bump stops (about 2/3 the height of the stock) per the widely circulated Budget Suspension Refresh thread on ZHPMafia. I also added the rough road reinforcement plates.
I'm due for an alignment, but as a stopgap measure, I made sure to meticulously mark the strut mount stud/nut locations on the strut tower before dropping the old struts, such that I could easily position the new strut mount studs within ~1mm accuracy of where the old ones were. So theoretically the only difference in geometry should be that small tolerance and the added thickness of the reinforcement plate (the old strut mounts didn't look deformed, and I'm assuming Koni made the damper outer casing geometry nearly identical to the OE). BTW I have the E46 M3 strut bar, so I actually removed those and the strut bar bases, and then switched back to the original strut tower nuts (the wide top-hat flanged ones) before marking the spots and lifting the car up. It would have been much more difficult to accurately mark the stud locations with the M3 strut bar tower mounts. Last photo shows an example: I used a fine pen to circle the nuts, and also drew little tick marks in the radial direction/aiming towards the center. When the struts were finally changed, I reinstalled using the non-M3 (aka wide) nuts, lowered the car, and then replaced with the M3 strut brace and associated hardware.
So far, these dampers are pretty nice. They unfortunately don't take up all the very
high frequency input from the subpar roads around where I live (possibly because not enough vertical force is generated to overcome the stiction within the damper itself), but I found that dropping my tire pressure from ~39 psi to ~34 psi helped in that department. These definitely make it so that you don't feel like you're "crashing" into speed bumps or divots in the road; I don't have to slow down for such features as much as I did in the past.
(I reattached the end link after this photo)
Marking strut mount stud/nut locations:
(strut tower tops are flat BTW, just the close-up shot makes them look deformed slightly)