After 1 mth, finally the B6 start to shine especially on 100-130 km/h speed. Now at that speed the drive feels like gliding even though a tiny less smooth compared to oem, but the change direction and stroke reserve is better than oe. The rebounce feels slower now so the ride feels less busy now compared when it was new. This also give advantage that I can increase the tire pressue up to 0.5 psi to maximise the grip without being too bouncy. The ride height also seems settle down a tiny bit and the car feels having plenty of grip now. So seems it takes a while for the shock to settle down, and hopefully will outlast the OE.