...or are they just a series of tradeoffs?
Conventional wisdom is that x86 has the raw power to keep the interface and everything else running smoothly, but unless you have a Gemini Lake or Gemini Lake refresh, that means no HEVC 10bit HDR due to the limitations of older HDMI standards.
Some ARM boxes and systems on boards have HEVC 10bit HDR recording, but it is difficult to keep up on what is actually working, and what is temporarily broken and decoding in software. (which seems to be a lot of Amlogic stuff temporarily due to moving to new kernels) I don't know how people keep up.
If everything in it were decoding properly (not sure if it is) the Odroid N2+ looks like it would be pretty awesome. Quite a powerful ARM chip with HEVC and HDR decoding support (once implemented)
Then there are the little Gemini Lake x86 boxes. They may be small Atom based cores, not the big Core cores, but they do have more advanced decoding.
Big X86 cores can probably brute force most things, but then we are talking heat and fan noise...
If you were shopping for a LibreElec box today, and wanted the best possible experience, price - within reason - not being a limiting factor, what would YOUR choice be?