Linear Audio Volume 4 has a long-awaited article by Jack Walton, comparing a large number of low power supply regulators. Comparison includes measurements and controlled listening tests by the New Jersey Audio Club.
The article has a several rather busy graphs with curves in various shades of grey. The readability could be better, so I regenerated those graphs in color and posted them here on-line.
Fig 5, positive regulators Line Rejection
Fig 6, negative regulators Line Rejection
Fig 7, positive regulators Output Noise
Fig 8, positive regulators Output Impedance