With 700+ posts here, it's hard to read them all at once, so I'm just gonna throw this out here...
At 1.1 damage ratio, DDD can chaingrab MK.
Wonder what other random things we can find out, huh? I mean, at first glance it wouldn't seem like that big of a difference, but timing for things gets stricter because of the increase in knockback (less true combos, harder to get out of attacks with low set knockback, etc), and the increased hitstun adds more to the game than what was there before (more/less chaingrabs with set/low knockback, faster kills by strong characters, less survivability for light characters... Personally, I find it much more of a drastic metagame-changing alteration than the addition of an air time/ground time time-out rule.
At home, and with a specific number of friends, I play Brawl as extraordinary as possible. I've played down to 0.5 damage ratio, up to 2.0, I've turned on handicap and played around, we still play in every stage in the game (I have a personal attraction to New Pork City and Summit), we've done items and varied from the most broken to the least affecting... I've even played in Summit in an actual tourney against one of those friends of mine once it was our turn to play! Those changes don't seem like a big deal theoretically, I mean, a x1.1 knockback increase doesn't seem like a big deal at all on paper, but in the middle of a match, there's a certain number of things that change, and player have to adjust accordingly.