I use the top of the line Mapleshade power strip, and find it is certainly able to enhance the performance of fixed power cord components from the good old days. I never compared it directly against other power conditioners, but it seems to rival even the more esoteric Quantum Octave 8 power conditioner, which it followed in one system. But, not a back and forth comparison, just overall system listening enjoyment rating.
Because the AC openings on the power strip are close together, the smaller non-hospital type power cord plugs of older components fit more easily between the newer, massive power cord plugs of modern components, so I am able to fully populate the power strip.