What a lot of people miss is that SMPS have wildly varying switching frequency, from below 20 kHz up to more than 100 kHz, depending on the model. If you look at for e.g Meanwell, their cheap models has a switching frequency in the 20+ kHz, too near to the audible band of the ear, while the more expensive ones switch at 60~80 kHz, less chance of harmonic distortion leaking into the audible band.

So I wouldn't sweat it, without knowing about the quality and switching freq. of the SMPS, I would take these comparisons with a grain of salt....