Somehow all the songs with Dolby Atmos tag sounds very impressive on iOS15 beta. On 14.6, the worst.
I hope that is the case. I am using AirPod Pro's on iOS 14.6 and listening to some of these songs that people are recommending, some of them sound terrible compared to the original, like Linkin Park's Hybrid Theory lacks any sort of low end, the separation of the instruments is completely off compared to the original mix. Same listening to tracks like Free Bird and Paparazzi. Some songs are just noticeably quieter, even with Sound Check enabled. I really hope there is some kind of bug in iOS 14.6 which is fixed in iOS 15 (or hopefully they release a patch - iOS 14.6.1 or something as I don't really want to run beta software). Generally, the newer pop albums and some of the old classics like The Beatles, Marvin Gaye etc sound good (I wouldn't say there are massive changes, but it is not so bad like some of the rock albums released in the 2000s which quite frankly sound terrible and make me keep off Dolby Atmos at the moment). I don't know whether it bugs or it is just a money grab by some of the labels and bands putting out some half-assed remix in Dolby Atmos just to get in the playlists. It may be a mixture of both as you would think Apple themselves would check these tracks before featuring them.
Some songs do sound pretty good, songs like Sweet Child Of Mine, a song which I know very well does sound good and you can notice some subtle differences, although as only two songs on Appetite For Destruction are in Dolby Atmos then there is a volume shift between Atmos and non-Atmos songs, which is a bug they really need to address.
Okay, one I have been impressed by is Tom Sawyer by Rush, I still love the original stereo mix, but the Dolby Atmos conversion is great as is Limelight. I would love to see Rush do the whole Moving Pictures album and do the rest of their discography. All rock bands take note, if you are going to remix in Dolby Atmos, check out what Rush did. Jackson 5 - I Want You Back also sounds different (not in a bad way). I feel there is slightly less bass than the stereo version. The most noticeable difference is the vocals. The vocals sound live, like you are in the room with the band which helps brings it to life a bit more, my only criticism is maybe they went a little over the top with the reverb, but it is another good example of what is possible.
With Dolby Atmos mixes, at the very least make it sound comparable to the stereo mix and maybe add some subtleties here and there (e.g. The Beatles, Marvin Gaye, Guns n' Roses, modern pop like Lady Gaga's Chromatica (not Paparazzi)), or make full use of the format while not losing the original fidelity and it not sounding gimmicky (e.g. Rush and Jackson 5).
Maybe Dolby Atmos and Spatial Audio will be the future of music, but like when the CD was first released there were a lot of CDs released originally that were just badly copied from vinyl. I hope the likes of Apple, Tidal, etc can put some pressure on labels and get some quality control.
Bands like Linkin Park, Fall Out Boy, Blink 182 etc sound terrible right now. Maybe they will sound better in iOS 15 and it is a software bug in iOS 14.6.