The way I live music is that there's an ever growing list of bands I care for, and an ever decreasing free time for music, with being an adult and stuff. Therefore I don't have much room even for continously listening to my favorite bands, especially when I heard those albums a gazillion times.
I listen to DT since 1999, so I have heard enough the old songs (if there can even be such a thing as "Enough DT") to not have really the urgent need to go back to them with all the new stuff that is out there.
So, save the occasionally nostalgia trip here and there, I don't listen to the older DT albums anymore. Heck, I'll forever call Iron Maiden my favorite band but I don't listen to their older albums anymore either, and the only time I listen to the likes of The Trooper or The Number of the Beast is when I see them live.
But for sure I don't see myself going back to When Dream and Day Unite anytime soon.