The geometry is a joke on sierras anyway so can't get any worse!!
It will make it more DIRECT, but some can bring HORRENDOUS vibration, as I found out, when I fitted SUPERFLEX here, (though they were ok everywhere else).
Saying that I have Deflex on my sapphy and they are ace, but still going back to std bushes with axle tightening kit(GGR) more expensive but I like it a lot better.
The TOE corrector shims will improve it big time, for so little outlay, £10 from R&B MOTORSPORT, this will make it more skittish as some call it, it just becomes a lot more responsive, and stops the dreaded inner tyre wear at the rear.
tabetha