I think it's a good list overall. The Brio is good, I own it. I demo'd Marantz, and the last gen is so smooth I couldn't consider it. I think it would probably be a good point to review the biggest amp release of the year, the Rotel A11 Tribute (Ken Ishiwata's last design). I imagine it would fit around 1-3 on the list above the IO and behind the 81.
I demo'd the Hegel at their lowest range and it is quite good. Superior black background and neutrality, without the prat of Rega. I don't think you'll be able to ignore them forever. Rega Elex-R vs Hegel H95 would be quite a showdown.
If the Marantz had a USB-B DAC input it would be in the running. The Yamaha-s801 is a bit old and doesn't really compete in dynamic performance or sparkle with a lot of these other amps (also a real life demo on my part).
I wonder where the Schiit Vidar/Saga or Ragnarok would fit?
I am, overall, partial to Rega's all-analogue PRAT design. But on demo I thought the Cambridge 81 was a masterpiece for its features and complete package. And I'm sure mixed with the CXC and CXN (considering chromecast for Amazon and youtube) you have a pretty complete system. Of course you can get that for lesser money.
An Echo Link + R2R DAC + all-analogue is a treat, but a full-system (one box) implementation would have good teamwork.
The Hegel also has digital features, it seems to be the choice of the younger audiophile with serious money.
It would also be good to review the Modi, doesn't Schiit have a European side?