The evidence is in the pudding. Try yourself and you may be in for a pleasant surprise. The $6K (N200) and $12K (N20) are not for everyone…OP asked for opinion between the two and the members with direct experience chimed in.
If I may, why ask for properly demoed evidence from members here than trying the two aforementioned streamers in your system? IMHO, If you’re happy with raspberry pi and don’t have any inclination to try a streamer like N200 in your system then no amount of empirical evidence would convince you or anyone. Plenty of users here are quite content with using their laptops as a source for streaming.
The only thing we can agree on is the origin of source file….this is indeed important much like rest of the components in your system. A well recorded file would sound good in any decent system but in a well put together system, you uncover nuances in that very recording that were previously inaudible or one didn’t know even existed.
In @jfrmusic system, the MACbook Air is a bottleneck given rest of his system. Stepping up to N200 would be a very audible improvement based on my past experiences. I have owned many Aurender models over the years, starting out with N100 and each time I stepped to next model, I heard marked improvement in terms of perceived detail, liquidity, transparency, pacing and noise floor. Did all of these nuances adds up to spending 2x, 3x or 4x more ….the answer to that would be very subjective and dependent on each individual pursuit. I’ve made my progression from N100 to N30SA….guess what, no regrets at all cause when I cue up a recording, my system gets out the way and I’m being treated with music and the story within each of those compositions.