I have "The Day of the Locust" Blu-Ray from Arrow and ran a spot-check comparison to the 4K/DV streaming version. They are strikingly different. The most significant difference to me is that the color in the 4K/DV version is more saturated compared to the Arrow disc; there is also noticeably...
"Revolutionary Road" has been upgraded to 4K/Dolby Vision on iTunes. Not sure when; I just happened to notice it and didn't see any prior mention of the upgrade in this thread.