My issue with waiting for raised level caps is some of those ridiculously high-level elite dungeons have certain characters' Record Materia.
Yeah, I don't play constantly so most of my characters are only around 30. I was able to get the Record Materia for Vivi and Wakka, but trying for Tidus and Garnet just wiped the floor with me.
"And if you don't, the consequences will be dire!"
"What? They'll have three extra hit dice and a rend attack?"