You're right on all your points except one: There is a difference in the CAP level for DSL and U-Verse. DSL is 150 G and U-Verse is 250 G.
Regarding Comcast. As long as Comcast and other cable systems continue to deliver content by a ring topology, information will continue to be compress into a digital blob with more packet collisions than actual packet delivery to the home.
I still despise AT&T's arrogant business attitude toward customers.