I bought my Gaz coilovers from K-Tech and never had any problems with them, then sold them on to Si aka CUPCAKE who did have a leaking rear shocker. Like he said, David was more then willing to send him a replacement.
David is the man to speak to regarding this, no-one else.
I have never had any issues from any of the tuners on this site, be it GDi, BBPT or K-Tech.
Keep up the good work chaps