I only have two sets in my 10.5" & 8.5" SBR's, but I plan on replacing all of my recoil assemblies with the Geissele Super 42's within the next month or so. The difference between the S42 versus Sprinco, or any other "premium" buffer spring assembly is very noticeable. First, the buffer tube noise is all but eliminated, secondly the gun recoils much softer, and finally simply pulling back the charging handle results in such a smooth motion you'd swear you swapped it out with a hydraulic system. this is such an overused phrase, but it's buttery smooth. In my opinion you should also buy the extra Tungsten weights, and swap them with the steel weights in the buffer. Before you compare the Tubbs Flatwire, don't, the two are very different feeling wise. Geissele has something special with the Super 42.