I have had a JSM kit on my Ty sense 06 and it has been the best bang for buck I've done to the truck besides the BS3. I have the QA1's and did not have to grind much inside the shock tower. I've put my truck through years of daily driving, drag racing, previously some pretty intense 16mile road racing courses. Multiple alignments, at least 4, still on the moog suspension components I used with the original install and ploy bushings. I frequently check my front end parts when I do oil changes. I've had to replace the front HUBs, but otherwise a outstanding kit.
I've seen 3 RPM kits and have installed 1, nothing but issues with the springs and spacers hitting the shock body even when loaded properly. I haven't been told a real fix for this other than replacing the spring and spacer combo with a new longer spring similar to the JSM design.
Sense all the QA1 and hypercoil setups, the Viking shocks stand out the most to me vs the original QA1/hypercoil setup. I have a RPM setup I'll be changing out to the Viking setup shortly and will report my results. I'm not knocking the arms, just the shock/spring combo just doesn't jive.
I've also recently installed a SM kit with the AFCO shocks and springs and think the OD of the spring is way to big for the tower. I'm not a fan of the afco shocks/springs. Way to close tolerances vs the QA1's and Vikings. The arms are quality, just was not happy with the fitment of the shocks. Makes for a difficult install and the OD of the shock body does not match the ID of the spring. There is a 1/4 gap on each side which allows for the spring to ride on one side of the spring cup/perch and put the spring in a bind/curve when loaded. I wasn't pleased with the decision to use that combo.
Anyways, that's my 2 cents. And I hope to hear more regarding people fixing there issues with the RPM shocks and afcos provided in the SM kit. I know the Vikings have been integrated into all three of the applications, I'd like to hear what shock and spring people are using with the Viking setup.