I would try all variations. With our SET amps, I've yet to find a power conditioner that didn't smooth over the sound, and that includes $300-5000 models. Didn't like the effect at all. With a 50W push/pull triode amp, however, the high end conditioner worked wonders. Separation and depth that were astounding. Currently, we have our CDP and preamp running straight into the wall, which is how we like it best. If we had different components, a different room, different ears...who knows? Only you can decide what works best, according to your preferences.
A dirt-cheap line conditioner will do better job than mega-priced powercord.
I've yet to find a universally applicable opinion in this hobby, including this one, with which I disagree.