I'm currently running GPMs on my Vorteks because I wanted a longer shock than the stockers and the price was right. For me, they've been fine. They did leak upon arrival (2 of them did), because the caps weren't tight, but that's a potential issue with any brand, including shocks on the car from the factory. IMO, they should just ship them empty and include a small bottle of oil if they want. I was putting my own in anyway, so that was a non-issue. I've not found bleeding to be a problem...they seem to bleed as well as any other shock I have personal experience with of the same kind of cap/bladder design. Maybe they have a small amount of air in them, but they perform great for my needs. The springs are holding up well so far and I haven't had any durability issues. I've got some ZD's on another rig, and I prefer the GPMs over the ZD's, as they just feel smoother and of higher quality, and to me they feel as good, if not slightly better, than factory 3s shocks. Personally, between my own personal experience and SOME of the negative feedback I've seen/heard, they're fine for general light-medium bashing and driving, which is what I do with my Vorteks, but if you're planning on sending your rig 80 feet through the air or trying to get a perfect tune for a drag car or rock crawler, durability and fine tuning is called into question. And maybe they're not the best option for heavier vehicles. For reference, I've got about 25—30 packs through the Vorteks since the GPMs went on, mostly at a BMX track. One session had a crash bad enough to snap the chassis, but the GPM shocks survived unscathed.
