Boobilee generates pyrotechnic explosions from nothingness (more like Boom-boom than Dazzler). Dazzler converts sound waves to photons, which is all kinds of fucky but cool as hell (and basically makes Monica Rambeau, but needs the sounds to make the light machine go brrrrrr). Also, Jubilation Lee used to be a vampire, but got better. Dazzler used to be a fun-loving disco queen and multi-platinum musician (who was oddly loved by the general populace for being a mutant), but then got grimdark and angry.
Tl;dr Jubilee makes fireworks from the firework dimension, Dazzler converts existing sound into light.