[Big Sky]

Lowering springs aren't "bad" per se, in fact they can improve performance (significantly in some cases), it is important to realize (particularly w/ a MacP setup) that lowering springs can also decrease performance in some cases.

Lowering is "good" because it lowers the center of gravity (cog), where things go haywire is w/ a Mac P strut as you lower you lower the roll center (rc) too- this don't lower proportionally, the more you lower the further the cog distances itself form the rc. The distance between the cog and rc is refered to as the roll couple- think of it as a lever- the shorter the lever the more the car will resist roll, the longer the opposite (refer to the diagram I linked earlier). Ideally you want to keep the lever short as possible, thus the caution of over lowering and the potential for decrease in performance. Obviously spring rates play a role as well, the stiffer the more resitant to roll- so as you lower you want to insure that spring rates go up.

I could go on, but basically if you keep the lowering moderate, increasing the spring rates as well- you will see an increase in performance. Don't keep the lowering moderate and/or increase the spring rates you could very well see a decrease in performance.