The TrueHD Atmos version however is way more refined. It feels like the bass is obscuring or overpowering the highs at the most intense explosions. The DD version is nice, but it comes at you like a wall of sound. Take the the elevator scene in the Matrix for example. With DD, you can either have very loud bass, or very detailed highs, but not both. There's a lot more headroom to deliver both powerful bass and the finest detail in de mid's and highs at the same time. Base is not necessarily louder or punchier, but just better. The TrueHD and DTS-HD/X versions are a night and day difference in quality compared to any streaming service. (Another example audio wise - yesterday I compared older CD rips of my favourite tracks (from the 80s) to the iTunes versions and in all cases, the CD rip (at 320AAC) sound so clear compared to the iTunes store versions which sounded dull, muffled and lifeless - really got me worried as the difference was huge.)

They are not for serious film lovers who want a permanent collection.

IF you can find the film on a 4K disc then buy that - iTunes films are for people like me who are more casual viewers (watch a film once a week or whilst travelling on my iPhone) OR like to rent a film for which they are great although rather expensive. I take the whole 4K iTunes thing with a pinch of salt as their PR tool and simply download the HD to my iPhone for travelling and as a back up. Given Apple's non existent iTunes customer service and the fact that they loose interest in their own products after a few years has made me question the whole thing. The fact that these 4K films on iTunes cannot be downloaded and can be 'removed' at anytime makes me question how good these will be for someone who loves to build a collection.

Dolby atmos test disk