I plan on being in the market for a R107 in the future and have given the bumpers some thought. I think the extended bumpers look heinous and ruin the lines of the car(kind of like the rubber bumper MGB's and many other big bumper evolutions). If it was a DD bumper damage might be more of a consideration but for a weekend/pleasure car I would go with the Euro bumpers or retrofits.
Edit: Did not mean to be so drastic on the extended bumpers-I just really like the way the Euro bumpers look