I have both front and rear H&R spacers, 8mm/wheel front and 5mm/wheel rear.
Advantages:
- better looks, fill the arches much better. On a stock LC/LFR the rear wheels look "buried";
- change slightly the ratio between front track and rear track and also very slightly the camber,
help with stability and understeer;
- decrease steering effort on the front due to change in angles of wheel alignment, at very fast speeds the steering wheel can be moved with a little finger.
~Nautilus