The new overtime is still a long way from a done deal. 24 NFL teams have to agree to adopt it, and that will likely be a close vote. The Colts have played two overtime playoff games this decade, and on the surface neither would have been affected. However, this is a case where had the rules been different everything might have changed. Let's look at the two games and see what could have happened.
2000 Playoffs Dolphins 23 Colts 17
The Colts opening drive of overtime stood at the Dolphins 42. On third and 12, Manning hit Harrison for 11 yards down to the 'Fins 31. There was also a five yard offsides on the Dolphins. Faced with a fourth and 1 or a third and 7, Colts coach Jim "0-6 in the playoffs for my career" Mora opted to go for a game winning 49 yard field goal with Mike Vanderjagt. Vandy missed the FG badly. The Colts defense, already exhausted from a 14 play drive to give up a 7 point lead at the end of regulation got run over by the Dolphins who scored the winning touchdown on the next drive.
Why the rule doesn't apply: The Colts won the toss
What would have changed? Maybe everything. In fact, the rule would likely have saved Jim Mora from himself. No coach would have declined a penalty in that situation if he knew that that a long field goal would not actually win the game. Surely, Mora would have had the common sense to either go for the fourth and one or more sanely, accept the penalty and take a 3rd and 7 from the 37. Given another play, the Colts could have either moved the ball into more makeable range (which for Vandy was about 25 yards if the kick mattered at all), or driven for the game winning touchdown. Honestly, I don't believe rules should save coaches from making idiot decisions, but then again, I hope never to have another coach like Jim Mora.
2008 Playoffs Chargers 23 Colts 17
The Chargers won the toss. They then converted two critical third downs. The first was on a screen pass that should have been stopped. The second was a questionable illegal contact call. They also fumbled on the drive. Still, on 2nd and 12 from the 22, Darren Sproules rambled for 22 yards and a touchdown to win the game.
Why the rule doesn't apply: The Chargers scored a touchdown. Under the new rules, the game would have ended without the Colts touching the ball.
What would have changed? Part of the reason teams give up 15-20 yard touchdown runs in overtime is because the defense is overplaying and trying to strip the running back. That's what happened on this play. The Colts defense knew that there was little difference between a zero yard gain by the Chargers and a 22 yard touchdown run. Everyone is playing to force a loss on the play or force a fumble. If the defense had the luxury of knowing that a field goal wouldn't end the game, they would have played differently. The Chargers had already turned the ball over deep in Colts territory twice in the game. If the Colts could have played their red zone defense straight up, they possibly would have stopped the Chargers. Forcing the Chargers to try and score a touchdown might have actually prevented their touchdown.
While I'm not as opposed to this rule change as I was when it was first explained as "first team to six wins", I'm still not a fan. I don't like having different rules for the playoffs than for the regular season. I don't care if a coin flip affects the game, especially because there is already so much luck involved with overtime anyway. The coin flip is 'fair'. That's really all that matters to me. However, I will admit that this rule could have changed the Colts' fate twice in the past decade.