Personally I would put Racingline, 034 Motorsports, APR, Leyo, Integrated Engineering all on the same level in terms of making very high quality parts. Ive had parts from all of these manufacturers and been very happy with their quality, performance and fitment. The only parts I was not happy with were some strut tops from 034 Motorsport, but all other items ive had from them have been great - so I was quite disappointed with their strut tops for my Mk7 GTI which knocked and rattled constantly.

Some of the suspension products that 034 offer are not really suitable for road cars (such as their strut tops and swaybar drop links) as they will be noisy and clunky - so just keep that in mind if buying suspension parts from them. But their swaybars, chassis inserts, intakes, exhausts etc are all very nice.

Id put Whiteline and Superpro on a notch below, with Superpro being the prefeffed brand out of the two. Still very nice parts (and nice that they are Aussie companies) but with Eibach, H&R and 034 Motorsport id say there are better products available.