I have two S540LTDs. One has a Steve's Special in the bridge and Air Norton in the neck. This to me is the most refined sounding set, my go to guitar for most things. The other has a set of Breed's, which are like the edgier, somewhat more aggressive borther of the PAF. I use this for when I'm in the mood for something more traditional sounding but with an attitude. Then I have an S520 that has Evolutions. The evos are just crazy. Really cutting and stinging. Anyway, YMMV.