I'm not in the market for a Mac Pro, but I keep thinking that something like this is the future for high-end computers—a capable base system with the ability expand virtually infinitely by attaching another Thunderbolt 3 component.
That sounds excellent. Fewer amateur hour broken, incomplete and potentially computer damaging implementations!
That they are all multiple specifications to bother with (you mentioned 4+others), and that they don't offer the full capabilities, speed and power draw TB3 does. Not to mention the ugly cabling.
>and real high end computers will make use of eSATA/SATA.
There's nothing unreal about a pro wanting an expandable portable compute to function as high end.