Brian, do a search on this site for "Sachs" and see what comes up. If you like the ride and feel of the car now, the Sachs kit amplifies it 3 times. Better braking, better handling, better everything.
If you are running 17" tires, it might seem a little firm over uneven concrete highways, other than that, you will be pleased with the result. Unless, you like the soft cushy ride the stock E34 offers and you have terrible roads in your area.
Another drawback is the kit will put added stress on other older worn suspension and steering parts, such as control arms and linkages. Doing the extra work along with the installation of the kit will transform your car like it was new again. Not to mention, saving labor costs while the front end is apart. If your suspension is worn enough to warrent replacement, chances are your other suspension parts are ready also. Might as well enjoy it as it was intended.
I don't think I've heard a negative comment from anyone who has installed this system. I sure enjoyed mine when I installed it on my old 535.
Good luck with your decision.
Jr