I have never used either but if you intend to grow in a simple unferted peat-based medium, that's what the AN soil line was designed for- specifically, for ProMix. It would also apply to Miracle Grow Organic if you add a bit of perlite.
I'm about to embark on a promix/AN experiment myself. We shall see how it goes, but the fella at the hydro shop, who I trust beyond simply his grow knowledge, encouraged me to run it for max efficiency just by following the 'recipe'.