Who has tried "TIDAL" vs other streaming applications?

+1 on how great Tidal is, but also +++1 on how great the addition of ROON is on top of Tidal. There is a quirk with Roon (or at least I see it as a quirk) that I have to ’add to library’ tracks on Tidal for Roon to then interpret the album or track as part of my music library (it's not actually downloading but more like 'tagging' music as part of my library). Because of this philosophy, I find Roon to be somewhat limited from a music-discovery perspective; I always have to go to the Tidal interface whithin Roon to explore new music, but it’s not a biggie really - still a quirk they should work on.

Most importantly though - the key benefits of ROON:
Roon properly interprets and manages classical music (Spotify or even Tidal doesn’t do a good job with this).
Roon supports a full, lovely iPad app that makes for a wonderful remote.
Roon shows music lyrics, album reviews and other metadata that is fun to explore while listening to the music of the band in question - it’s a great accompaniment to the listening experience.
Roon supports technical integration with things like HQPlayer, allowing me to upsample all Roon tracks to DSD on the fly.

The last point above is HUGE, as it allows me to play all music via DSD 128 via my Lampizator Big 7 chipless DSD dac. The resulting sound quality is jaw-dropping. I paid the $500 for livetime Roon membership and I think anyone who doesn’t is pretty shortsighted, considering we spend more than that (in some cases orders of magnitude more) on the likes of an interconnect or some audio accessory.

Tidal has been an amazing step forward in the music experience vs. what came before it, but Roon (plus HQPlayer plus Lampizator chipless DSD dac) is a revelation and takes things to a whole new level.

@outlier , I bought an iPad Mini 2 to control my music using Room on Tidal. I read on a support thread in a Room forum that my iPad needs to be 64 gb. Mine is 32. Is this true?

Damn spell check. Meant "Roon".

With my system, I can clearly hear the difference Tidal HiFi vs High, but if someone changes my setting secretly, I have little confidence if I can detect it . lol.

A minority opinion here, I suspect.  You can attribute it to what you will...inadequate gear, the wrong set up, old ears and degraded hearing.  Just spent a good amount of time over several days of a "free" 30 day Tidal HIFI trial A/B-ing tracks (and small sections of the same track) on Tidal vs Spotify Premium.  Took pains to get volume levels the same (RadioShack SPL meter). Listened on the main system with Gungnir DAC (not Albert Porter's but good enough to hear cable changes and differences in various issues of an album) as well as headphones (Senn 600/AQ Dragonfly/Asgard 2 amp).  Based on enthusiasm from the Tidal fans here and elsewhere in A'gon, was expecting a night and day difference.  Personally, I was underwhelmed.  I thought I might have heard a tiny, tiny bit more hi end, separation, and density to the music but emphasis on tiny.  Switching back to the same track or section on Spotify Premium and that "remembered improvement" evaporated in a second.  It wasn't like the sound stage shrank or high end started sounding rolled off accompanying a noticeable degradation in SQ..  I doubt I could pick out Tidal vs Spotify in a blind test.  So FWIW, that's my story.  Was really hoping Tidal would bring a step up change in sonics but it didn't for me.  Cancelled the trial.  Saved myself $20/month and kept Spotify which I find very satisfying.  Happy listening to you in which ever format you choose.