Horses for courses. As John Broskie of TubeCAD points out, series regulators are well suited for class AB power amplifiers, where the current demand on the power supply can vary from tens of mA to several amps, whereas shunt regulators are best suited for class A amplifiers where the variation in current demand is relatively limited.
Arguments about which “sounds better” approach religious discussions, although it is interesting that more designers claim that shunt regulators sound “better” than the reverse – for example, Broskie, the late Allen Wright of Vacuum State Electronics, Richard Marsh, the late John Camille, designer of the Kyrie 211 SET amplifier, Lynn Olson, designer of the Amity, Raven and Karna, Kevin Carter of K&K Audio, and Frank Cooter. I think Kevin Gilmore is one of the few designers who has gone on record saying that series regulators are as good or better. Incidentally, Richard Marsh wrote an excellent basic article on power supplies for Audio Amateur magazine (1983, issue 3).
Religious arguments aside, there are pluses and minuses to both approaches.
In favor of series regulators, they can have excellent specifications in terms of noise, output impedance, input rejection, etc. For example, the low voltage regulators designed by Walt Jung have a lower output impedance than 0.2” (yes, one fifth of an inch) of 18 gauge wire. Of course, to achieve that performance you would have to incorporate the regulator circuit on the amplifier board, as any intermediate wiring would negatively affect the impedance. Series regulators are frequently more efficient than shunt regulators as they only require a few mA extra current draw for regulation.
In favor of shunt regulators, they have a constant current draw from the raw power supply, can both source and sink current, and have a relatively simple path to ground. By using a constant current source in series between the raw power supply and the shunt, this limits the signal currents to the regulator and amplifier area, whereas the varying demands of a series regulator means that some simplified form of the signal current has to circulate between the raw power supply and the series regulator.
The argument that a shunt regulator can both source and sink current is thought by some to be a major reason for its sonic superiority. However, this can be abrogated to a significant degree by placing a bleed resistor after a series regulator to bring it up to 50% of maximum load, as first suggested by Richard Marsh. This allows a series regulator to also source or sink current up to the level of its bleed current, but also decreases the efficiency advantage of a series regulator.
For a phono preamp, which runs in class A, you definitely want low noise. The GRLV definitely qualifies for that. K&K Audio sells a shunt regulator kit which it claims is suitable for phono preamps, and says it is based on the Salas regulator, so I assume that it is low noise also, though without suitable measuring equipment it is impossible to know how they rank in terms of noise.