I'm actually on a tight budget and have the stock one still, although was looking into getting the Mugen one. As far as understeer goes, it's front wheel drive, and you'll always have some to some degree, but with those spring rates, driven correctly, the car rotates very nicely, and really doesn't plow almost at all. Any one who has compaints about understeer with very stiff coilovers, probably is just coming into the turns too fast, and isn't doing any trail braking to get the car to rotate a little.

Later,
Aj