QA1 has extra caster angle about 3 degrees this makes a big difference in handling and steering wheel recovery , they also have polyurethane bushings where stock ones are rubber . I used to feel every little bump in the road and you would feel it in the steering wheel, what a difference now with the QA1 upper control arms . The uppers are well worth it. Just my opinion .:)
You can get that caster with the offset upper control arm bushings. I suppose you would want an aftermarket radius bar too. I wonder what the weight saving is. I would definitely go the QA1 route if I had more money. Borgeson box would be nice too.