Hi Andy:
Some of us use our own valving that works pretty well,....
I would mention that the ability to raise front spindles is IMHO, a biggie. This does several things such as restoring lost shock travel when the car is lowered and raising the front roll center back up to reduce front lateral weight transfer and help keep the inside front wheels from lifting in a corner.
Koni shock shafts can be shortened a bit but that doesn't address the roll center problems when these cars get lowered to handle better.