my only problem with itunes movies is the sound quality
I get the impression that, that is the studio's fault and not Apple's. I've rented only two or three where the sound has been lifeless and so compressed - however 'Call Me By Your Name' and 'A Bigger Splash' both by Director Luca G absolutely SHINE in their audio and are truly amazing - both 1080 HD iTunes files. It's very clear that sound means the world to this director along with his absolute beauty of filming with a single lens camera.
If anything, it's the big mainstream Hollywood tootles that really sucks whereas all of my independent surfing films sound crisp, clear and beautiful.
It's clear that many of the big mainstream Hollywood titles will have Dolby Atmos, so with Apple using the DD+ format, the sound should be of a decent quality from September onwards
I always remember the first time that I heard audio on a DVD in 2000 and I was absolutely horrified. I'd come from Panasonic HiFi Stereo VHS video recorders were their sound was truly incredible - full and dynamic. DVD sounded so thin, quiet and compressed in comparison. I remember having to turn the TV volume up to 80% just to enjoy the film. Gosh, I really do not miss DVDs. 10 years too late for those things.