Some notes from someone in the industry...
The 'enhanced' version is not yet used, everything out so far is using the basic AACS2, it is unknown exactly when the enhanced will be available for use. Knowing how past AACS requirements have never materialized, I actually wouldn't be surprised if this never really takes off. Also Fox is really the only studio I know of that is interested in this. They are also the only one I can think of that uses BD+ regularly, and are more technically minded than other studios.
Streaming is no where near the quality of these discs. Someone posted that Netflix streams 4k at about 16Mbps, while the video on these discs will be over 100. Also the bigger aspect of video on the UHD discs is bt.2020 HDR color space, which I don't think Netflix does yet. M-go is the only place I know of that has similar quality video, Fox tries to use the same encode on the UHD BD as they do for their "Vidity" downloads on there. Also if sound is important to you, I don't think anyone streams Dolby Atmos or DTS:X audios.