Hate to rain on the parade but there's really no comparison on any level. Not buffering, not plant nutrition, not durability.
If you can afford Aquasoil, get it.
Buffering: ADA wins that one and it'll last a couple years
Plant nutrition: Fluval Stratum contains next to nothing, so you'll have to use root tabs
Durability: Stratum breaks down much more easily than ADA