Using a Beyerdynamic 1990 Pro headphone, a JDS Labs El AMP II and Atom headphone amp, I listened pretty extensively to Amazon Music HD, Qobuz (with its own player and through Audirvana) and Tidal HiFi / Audirvana. For available library, 1. Amazon Music HD, 2. Tidal HiFi, 3. Qobuz. Just randomly searching for sometimes lesser know albums from 60's through the present, I was more likely to find what I was looking for on Amazon Music HD, with the most "missing" selections with Qobuz. I found Tidal to have a library just a bit behind Amazon Music HD. Comparative sound quality for me was 1. Qobuz/Audirvana, 2. Amazon Music HD and 3. Tidal HiFi/Audirvana. Truthfully the differences in audio quality were not profound, when choosing and playing songs with the same audio specifications. Qobuz/Audirvana, although difficult to describe is, for me, a bit better in audio quality consistently. Player interface/use 1. Amazon Music, 2.Qobuz/Audirvana and Tidal/Audirvana tied. Tidal HiFi was my first cancellation, being the most expensive and having a heavy emphasis on music genres I have little interest in. Currently listening the most to Amazon Music HD, which is not available on the Audirvana player, but Qobuz and Tidal both are. Actually currently liking the Amazon Music HD player more than Audirvana. I'm leaning towards cancelling my Qobuz subscription, as it has more missing albums and costs a bit more monthly than Amazon Music HD. I have to chuckle occasionally, when comparing costs for subscriptions for these 3. I haven't purchased an actual CD for a couple of years but for the cost of one CD, with any of these programs, I can listen to many dozens of albums per month. Beginning streaming has definitely renewed my interest and excitement for music and music equipment. Have to admit that I quite often do feel more than a little guilty, taking advantage of the music streaming world, as it definitely must have resulted in a major loss in earnings for the artists. I guess for the more popular performers, the money is now in concert revenue but COVID-19 has pretty much ground that to a complete halt.