Will the DC's have level 5 coils? You might actually be underpowering a HDC3 with 1500 watts but with a DC might be a little to much power. For a stock one. A level4 with level5 coils could handle the 1500.
//content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif the DC lvl 4 is more spl oreinted, it does sound decent but it will deffinitly get loud. I have mine with lvl 5 soft parts and on 1500watts and she getts pretty loud. iirc my box is some thing like 2.75 @33HZ
also the HDC3 i have no clue but I do want one to see what people are getting a boner for.
Are you talking lvl4's or lvl4 xl's?? Frankly I like them both. I prefer the DC's but both will get loud. And if your worrying about which will get louder. either will sound fine for you.