Assuming the information coming out is true. Anyone arguing the Pats side of this, is a blatant and biased homer. There's no excuse. 11 of the 12 balls were found to be about 2 PSI under-inflated. That's 16%. That's a big difference. The amount it helps both grip for passing the ball, and the softness for catching is big. And the Pats passing game is based on short passes, and crossing routes. A deflated ball decelerates faster when thrown, so one couldn't throw it as far, and it might hang up a little on deeper throws, but on short throws, it is a huge advantage, to not be trying to throw and catch a rock hard, wet, cold, slippery ball. I played QB in high school. A harder ball sucks to grip and throw in cold weather unless you have massive hands. Hence the reason many QBs deal with wearing gloves in the cold weather.
Would the Pats have won without this advantage? Obviously. That's not the issue. They cheated. They made sure that if it was a close game they would have had an advantage. How do we know they didn't do it against the Ravens too, where a slight advantage would actually have been the difference between winning and losing. Is it a massive advantage, unlikely. But why the fuck would they do it, if it didn't provide any advantage at all? They wouldn't.
It's like bribing a referee to make sure that you win, but then you go out and dominate the match anyways, so the referee doesn't actually have to help your team. You still bribed the referee. You hedged your bet. And that's exactly what the Patriots did against the Colts. They were clearly the better team, but as they say "Any Given Sunday", so the Pats made sure that even if it was a Sunday where they had an off-game, they would have whatever advantage possible. They cheated. Plain and simple.
Again, assuming the reports are true. If they are, Bill Belichick should be suspended for the Super Bowl, and the Pats should be fined massively and lose several years worth of first round draft picks. If Tom Brady was involved, he should be suspended for the Super Bowl also. Blatant cheating is detrimental to the integrity of the game.