I think the current system is very good. It allows for a grading in week 1 of the top 8 sides - with games getting 'easier' the higher you get. The 2nd side gets a 2nd bite of the cherry. 3rd and 4th are relaitvely safe, but on a diminishing scale. 4th v 5th is a tussle. 6th, 7th and 8th have to prove their worth v top sides, with only 6th with a chance to lose, and not be eliminated.
Week 2 is where the Mac system gets it's critics, with the crossover. This is where a still alive 7th can play, say, the 5th placed team, while 4th cops the 2nd placed team. (this happens when 7 beats 2, and 4 beats 5 in week 1). BUt if 2 loses in week 1, they deserve to have a harder run. However, 4, as a reward for winning, plays 2, while loser 5 gets to play 7. That's the problem.
In comparison, Ryans system robs any advantage of coming second, as opposed to the top 4. In a top 8, I thinks it's fairer that 2 teams have a week off, rather than 1. Under Ryan's system, the team with the week off sits and recovers while another 6 teams battle it out. This give's it a big advantage to make the GF. Team 2, therefore, is little better of than the rest.
I like the fact that teams 1 and 2 have the double dip advantage, and by mathematics, 3 and 4 also have the chance. 5 and 6 can guarantee success by winning, with a slight chance of reprieve if 7 abnd 8 lose. And 7 and 8 need to prove themselves by winning against a gun side to enter the rest of the finals.