The cheaper Meanwell supply arrived earlier in the week and I've been trying various combinations, but ultimately, it doesn't compare to the iFi iPower Elite. The Meanwell definitely improves pretty much every aspect over the stock power supply, but it doesn't affect bass as much as the iFi. Bass is tighter and more impactful and there's much more microdetail/plankton with the iFi. Music sounds more realistic and alive vs. the Meanwell.
I have an iFi DC iPurifier2 that was plugged into my Pi2AES, but I removed it and was using it on the RHNP. It did not work with the stock PSU at all, but has no problems with the Meanwell or iFi units and, surprisingly, it makes the same noticeable difference regardless of which PSU is used.
The biggest place the DC iPurifier2 improves is the highs; there's a ton more detail and separation along with a pleasant smoothing that doesn't cause smearing or loss of detail. Even with the iFi PSU, treble (cymbals in particular) could get harsh/static-y and even painful if volume was on the higher end of comfort, but since putting the DC iPurifier2 in place, I haven't had any of those issues anymore (aside from just listening too loudly). In addition, imaging is a bit tighter/sharper and there's a better sense of "openess" as well. I didn't notice any change to bass, however.
I think the Meanwell is a great upgrade, especially for, what, $15? It definitely does improve over the stock PSU. I can't say for anyone else if the iFi Elite PSU is worth the $300, but for me, it absolutely is. The improvements to bass make me very happy. And I think regardless of the PSU used (aside from stock), the DC iPurifier is a great addition.