I'm somewhat skeptical of the tuned-kernel movement, so I didn't install it expecting to make my OS "fly" or anything. It just happened that recently there had been some weird kernel error messages ("perf samples too long"), and, related to that or not, the OS would become sluggish with lots of read-or-write activity (on my old HDD that must be really slow, to add to sluggishness). Apparently you can sort of solve it in a sysctl-like way, printing a "0" to some file/parameter,...
