Originally Posted by Porschefile
From what I have read the GC option is the best, and includes very good camber plates. If you are tracking once a month that is fairly frequent, I do a similar rate and settled on KW CS for my purposes.
If you buy used V3's or something for under $2k they'll hold their value too, that is the way I looked at my situation. Good suspension is an investment (though not an appreciating investment
To address your question of whether the kits are better performers than just springs: The GC kit definitely is because it includes aggressive camber plates that cost $500 alone. Your car will turn in much better and wear the tires more evenly with some negative camber dialed in. If I was choosing between those 3 options only, GC.
The TCK kit also comes with Camber plates:
both the GC and TCK kits come with linear spring rates compared to the KW kit which has progressive. Thats also something to think about.
I personally decided on the H&R Sport springs with e36 bump stops and removing the rear spring pad setup on my ZCP (cost was $175 for the springs used, + $50 for bump stops, and $5 for rubber hose to replace rear spring pads total of $230). My plan next is to add in the camber/caster plates to finish it off. I havnt tracked it but so far on the street I have been very happy with it. A buddy of mine has the same current set up I have on his E92 and hase tracked it a few times and was very happy with it, but he is also running the modified upper mounts up front which I didnt do (modified mounts add a little more travel).