For the OP, as noted above, all electrical questions in high end are ... complicated. First perturbation, though, I'm inclined to believe that the elasticity of the drive belt would tend to filter out any micro-differences between a well-designed SMPS & LPS outputs.
That said, I'm willing to assume that: 1) SOTA carefully chose the wall wart they currently use, and 2) they believed that an LPS *could* make a difference, tried it, and feel that it did. Maybe they'll let you try one out?
Good luck with your decision! Please let us know if you take the leap.