okay I'm pretty set on the Koni's and the BAT 25mm sport springs... from searching, it looks like it's a good idea to replace the upper strut mounts at the same time. My car is a 2000 SVT with 50,000 mostly city miles. I drive the car very hard but try to treat it really well when I can.
Scare me! What harm can I do by not replacing these mounts??
Are we talking vastly increased wear on other components, possibility of failure, 1% or maybe 20% loss of some performance aspect, increased tire wear, simultaneous combustion, ???
Give me a low and a high, i.e. "nothing really it's kind of a good idea" to "approximately 10% loss of bound/rebound strut performance and possibility of mount breakage.