I would tend to disagree with the statement that most components have "line conditioners" built into them. Most have some sort of fusing, but that's not enough to provide complete protection from power fluctuations. Depending on the electrical service in question, line conditions may or may not offer any audio/video performance benefit. My Panamax MAX5100 helped some with sound quality in our old house (which had some iffy wiring), but I haven't noticed any difference in sound or picture quality when I swapped it out for a Belkin PF60 earlier this year and don't know what difference the Panamax might have made in this house (never ran the system without it present). As nomoneybutgoodsound points out, though, surge protection is a significant reason to have something decent between the wall and your gear.