Hello all,
HiRes is pure marketing. I don´t mean to offend anybody but this is “wanking with numbers”. The higher the better 
. I would even go so far that nobody is able to spot the difference between 320kBit ogg (i.e. Spotify premium) and flac of any bitrate with 99,9% of the presented material in a double blind test. Here´s why:
The problem with human hearing is that we don´t hear with our ears but with our brain. And that is in most cases knowing what is playing, seeing the glossy expensive gear vs. some well constructed and assembled DIY speakers which measure objectively better but unfavourably lack a walnut finish and golden spikes.
People who clearly express their dislike for lossy music formats simply don´t understand psychoacoustics, which is mostly the principle of auditory masking (https://de.wikipedia.org/wiki/Maskierungseffekt, in German, but there is an English version, if you prefer) which is inherent to every human being.
Of course there are dramatic presentations on the net that there IS a difference (obviously, where should the data go?) showing “diff”-Files which are quite impressive at a first glance. “Oh my gosh, I´m missing all that stuff?”. Yes you are, but your brain would have sorted it out anyway.
This is not an exact analogy but more apparent than auditory masking: Imagine coming from outside into a dark room on a bright sunny day . You almost don´t see anything until you eyes get used to that. That is (sort of) why you are not able to hear silent - in comparison - content while the loud content dominates. Of course you can clearly hear the “diff” content alone, but only when the rest is not present.
So the theory behind that is: When you KNOW, what you are listening to, you have a clear preference for “more horsepower” (which is HiRes in our case), because it must be better. You paid more money for it in the most cases anyway. But that is subjective. If you are lucky with that, I don´t mind. Most products of the so called “audiophile” industry would not sell, if our brain wouldn´t play that trick on us.
OT: The burning in / breaking in process is the same. The only thing that breaks / burns in, is our brain. Simply speaking: we are getting used to the sound after some time. There is no part in the hole audio chain which changes its behaviour over time (but over temperature 
).
44kHz/16bit Is more than sufficient for playback. 96kHz/24bit is needed while recording because it gives you more headroom for mixing. But yes HiRes files often sound better, that is because the recording and mixing was done with a great deal of care and knowlegde, and since: why not selling it as “HiRes”? It´s there anyway, it meets the demands of the customer and finally you can make more money.
Modern lossy encodings are not the devil, because they respect the science (physics, biology, psychology). The higher the bitrate, the more far the “lost content” is away from the audible threshold. That was not the case in the early days of mp3, which was sometimes poorly encoded with audible artefact, so please don´t refer to that age.
My background: I´m an acoustic engineer in automotive with a passion for music and good recordings. And a clear dislike of anything “voodoo”-ish some clever marketing is trying to sell to us for lots of money. I build speakers for over 20 years. Most of the time I listen to spotify and I´m happy with that. The reason I sometimes listen to CD is: The streaming provider of my choice tends to have only remastered versions of old material. Unfortunately this is mostly done with reduced dynamics as the modern customership, mostly listening to music on smartphones, seems to like that more.
I also listen to vinyl but, since this is objectively inferior (dynamics, SNR), because of the special sound and nostalgia. Like some people (not me) prefer tube amps. There is nothing wrong with that as long as you know, what their physical shortcomings are and why that is so pleasing to some ears (brains! 
).
Cheers from Bavaria
Arnd
EDIT: typos removed and refined some expressions since English isn´t my native language 
EDIT2: After refreshing my knowlegde, auditory masking is not only done in the brain but also an effect of the mechanics in the ear and the neural signals, sorry for omitting that in the first place.