I've installed the RCF GSF lower control arm brackets and it made a massive difference, the front end is a lot more stable, the car tracks much better, cornering and braking has improved a lot.
Before I was finding that I always had to correct the steering due to bumps and uneven surface on the road. I've also read on the US and Austraila forums, a lot of guys have swapped to RCF GSF control arm bracket with very good results.