I have the QA1's on the Scamp with about 30,000 miles and the only issue I have had is the spherical rod end starting seizing about 10,000 miles ago and squeaks and groans.
Just ordered the PST's for the Duster, and the front clevis looks to be about 3/16" steel, formed into a "c" channel versus the QA1's which have a machined aluminum clevis, which looks like it might be stronger.
The PST's have an Allen head bolt that screws into the center tube on the control arm end,versus the QA1's which have a stud and nut arrangement.
Just from the looks of the 2 brands, it appears that the QA's might be a little better design, but I have not installed the PST's on the car yet.