Alot of folks report 50-100000 miles no problems street /track, and thats with XA's as well as BC coilovers. Alot of those with G8's say the same and they have more time and miles in to.But you can have a bad set, it happens. I had konis blow in the rear over a big dip on the freeway at speed, but car was lowered and bump stop was cut down(per experts advise
) AFter that and replacing stops, no problems.
Alos I hear running the settings to high all the time will wear them sooner, but not blow them I dont think.
As to quality, other then Pfadt, all are made in Asia somewhere. In my industry and others, quality can be up or down and not consistant
Mods: Magnaflow 3" comp catback/Rotofab CAI/Apex Scoop/VMax T/B/ G.M. Blade Spoiler/SLP Splitter/ Forgestar cf10 wheels & Michelin Super Sport tires/JBA Shorty Headers,HiFlow cats & tune/ Pedders Supercar coilovers and Pedders 27mm/32mm sway bars /BMR cradle bushings, toe links and trailing arms/Stage 1 cam-445/427 RW HP/TQ