The inclusion of automatic qualifiers is probably the most objective criteria there is - you win your conference, you are in. IMO that is how it should be. If a team cannot win their conference, they should not get an automatic bid. Don't care who they are.
The SOS and SOR are not objective at all - go look at the numbers - most of the teams with the top SOS are not in the playoff because they lost too many games because of the SOS. A lot of teams with a good SOR have a lower SOS - probably why they won so much because their SOS was not that difficult.
Who is the best is completely subjective, always has been.
I do think the current model does end up with the top 4 or 5, maybe 6 teams in the mix - which was the goal of going to 12.