I havent heard the DD1512 but it will be able to hit lower than the mtx 7512 44 which will only drop to about 38 - 40 hz
I do want to make a correction that I didnt think of on the mtx 7512 vs kicker cvx post....the 7512 44 will not do well on rap music below the 38 - 40 hz range and if you dont have a subsonic filter to protect them they will sound bad trying to go below that and get damaged eventually
All are accurate woofers. I'm not sure how these woofers compare on paper but with that being said... At this level I think maybe user discretion is important. Some people prefer metallic tweeters where others prefer synthetic....all the woofers you listed there are great woofers, but maybe with different sound qualities. Myself?, I think I like the Focal, but without listening to them first hand to compare them my opinion means nothin haha.