Sub question

I currently have a kicker cvr 12 inch sub in a sealed box. I'm thinking of going to a kicker l7 in a ported box. Keep in mind this is in a pontoon boat...my question is the cvr is 400 rms sub. The l7 is a 750 rms sub. Will there be any advantage to switching subs.say they are in a proper box is the l7 gonna be worth changing subs and amps. The sub is under driver console and points out to the left side of boat..I listen to rap rock country. I usually only use the sub on rap songs with lots of bass but when I do use it I want it loud. Do you think the switch will be worth it or keep what I got. Thanks