Jeff Rowland has been refining his custom power factor corrected SMPS designs for decades, and uses them in his best amps for ultimate performance and superior sound quality compared to linear supplies. A far cry from the common noise inducing cheapo SMPS which cause many people to condemn the entire concept.
Chord and Linn has always been big proponents of SMPS designs.
I have once spoken with Dan D'Agostino about those and he said he likes the idea and maybe he will design one eventually, but his own way (read: totally overbuilt).