You may have gotten lucky, or your struts were actually wore out and you never knew it. In fact, with 100k miles on stock springs, they were probably already very worn out. You're lucky to have never encountered any seriously bad affects from it.
I put used (~60k miles) svt struts on with roush springs and within a couple months the rears were shot. I don't mean there was oil coming out of them, but the handling/ride was diminished. It also caused the rear to want to step out one day all on its own.
All experiences vary. It's quite possible for one to be satisfied with stock struts and lowering springs.
