PD-Creative

I have not. However, if you are changing power supplies; you should know that they are not exactly the same and and will influence overall performance.

With regards to power transformers- those will all do the same job. However, some will outperform others.

The same is true with capacitors. This is why for lower-end vintage amps, swapping caps makes sense.

What separates a multi-thousand dollar amp from a much cheaper one? The quality/reliability of internal components.

I mostly agree, having experienced this and learning how audio signal amplification works.....HOWEVER, as I use my Node 2i ONLY as a streamer, I wonder how it would make a difference.  No doubt the noise generated by a new power supply would be significantly lessoned, but does this end up mattering in a digital streamer?

OP, 

Whether it matters or not is like asking if a new (larger) intake valve would improve the power output of a car engine. 

Higher quality internal components in general are going to lead to better objective performance. There is a reason why mega-buck components from the biggest names in audio refrain from using cheap power supplies and rudamentary caps etc. from China. An amp that costs only a hundred bucks and claims to be a "power amp" probably isn't; and comparing it to one that costs many thousands of dollars is going to lead to finding many differences between the two.

In the end, almost everything audio matters. However, above all your perception and enjoyment are far more important.

I ordered the Creative board and budget power supply combo and it took just a few days to arrive. I Installed it last night and gave it a listen for a good hour today running through an MHDT Orchid.  Even in a doubtful, hyper critical frame of mind I found it sweeter on top, tighter on the bottom, much better focus, clarity and inner detail, especially strings and choral. It really won me over.  Smooth. Punchy.  I could feel my ears relax and the sound open up.  For $126 delivered it’s a bargain.  

@wlutke ya man, way to go !thanks for the informative real world post !