I bought my Yellowspeeds from Ken about a year ago, and so far they havent let me down. I even tweaked with dampening for awhile and right now I have it set to recommended street settings.
As for the endlinks, my rear endlinks were rusted, so I ordered AWR adjustables, my sway bars are still stock, but the installation was easy.
My Front endlinks; suprisingly they came off easy, so I reused them. But after i got my alignment done, like how some people had come across, my driver side endlink bent. So, I a stocker from autozone and installed it, ordered some AWR one for back up just in case. but since then no bending.
Right now my P5 is in the middle of a rebuild so on my down time Im going to change out the front endlinks for the AWR's
As for performance, it is a well built system for those who want a street car that you can take to the track and tune real quick. As for hieght adjustability... you can get about a 3 inch drop, which probably isnt low enough for those who would want a drop of BC's or any of the other competitors, and the spanner wrenches that came with it are garbage though, it came with 2 and I am down to one. but overall, the system is worth it.
there is one minor thing that gets to me about the suspension, is when you have the front up on jacks, the sway bar and your endlinks rest on the lower control arm. but as soon as you put wieght on wheels, it levels out and looks real pretty.
hope my little write helps people in the decision on purchasing Yellowspeeds or any other brand that you might consider.