Thanks, I had no idea eGPUs were a thing!
It's the only non-Pro designated Mac that has four Thunderbolt 3 ports. I don't think you'd find this level of I/O in any other machine in this price range.
That incredibly powerful I/O makes for tons of expansion possibilities. Storage, GPU, etc.
(Edited to say "non-Pro designated")
* Mac Pro
* Mac Mini
* iMac Pro
* MacBook Pro 16"
* MacBook Pro 13"
I must have mixed it up in my head.
The point being that a "Pro" system might have 4 individual Thunderbolt controllers, each getting their own 4x PCIe 3.0 lanes.
I think that's why the specs say "Up to 40GB/sec" on the page. It sadly doesn't say which controller it has... But I guess my whole point is really moot in practicality. Good luck saturating that much bandwidth.
The Mac Pro starts with two controllers but can be configured up to six.
The I/O is actually pretty good and provides for a ton of headroom for expansion down the line (I'm thinking primarily storage and GPU for my use-case).
I can see a pretty high powered eGPU saturating the lanes.