re audio xxx18

Hello everyone, 5 yeas ago I bought a Re Audio se 15 D4 with the amplifier hollywood hxa 3k, so I was using 1200 w rms at 2 ohm. I was thinking to buy a Re Audio xxx18 D2 and use the same amplifier at 1 ohm (1800 w rms). Is it worth to buy this new subwoofer if I already have that one? Is it...

I am in between subwoofers but these are the 2 that I think I have narrowed my selection down to. I know that these are both supposed to be more geared towards sound quality, granted 1 more than the other (the lms), but I was hoping maybe some of you had experience with both of these subwoofers...