Alternatives to the current first auction fee model

I’d love to start the discussion on replacing the current first auction based fee market we have for transactions. I think it has many inefficiencies and is also a major UX barrier for adoption. Perhaps first we can start by collecting all the valid proposals that are out there. The two I’ve seen so far are:

-Vitalik’s proposal which introduces a real-time fix fee model based on how full blocks are

-A proposal by some people at Cornell where users can bid for fees in a block but everyone ends up paying the lowest accepted fee.

I see the transition to Proof of Stake as a great opportunity to replace this model so I think getting some momentum behind it now would be good if the community can agree on a certain approach. We could leave the PoW chain as is.