my vote: I use both... Actually I use pumice, perlite, and vermiculite (heavier on the perlite in the seedling mix, and heavier on the pumice in the growing soil; I use heavier vermiculite in the seedling mix, but still use it in the growing soil)
I used to use both, but the vermiculite doesn't drain well enough in high temp, high humidity. The soil remains soggy, and too heavy. When I kicked it, everything went great. Except during low humidity dry season, when I have to water every day. LOL
