I have been using the component DiDs under my ModWright modified Oppo BDP-105, PS 9.9 power supply, and LS 36.5 for about a year now (all of my tube components). They do make a noticeable difference in extension, bass clarity and depth, soundstage, and detail. I haven't tried the speaker DiDs yet but might at some point as I've heard very good things about them as well...