Plenty of things or nothing... And that is my main issue with potting soil. What you use for potting soil is different than what I use, this will definitely influence the development of the substrate. (Even in the same brand I've seen differences from year to year.) Here I am referring not only to consistency but also the actual substances in the substrate.
Ada AS is much more consistent, standardized across the globe and thus the results are more predictable. Every soil tank developed differently, ADA AS not so much.
Even broken down As settles much faster than soil.
With decent cleaning it will not go anaerobic, soil rich in organics is much more likely.
Which one is more suitable for you? That is a different question and depends on goals and limitations you want to work within.
Most / all aquatic plants grow fine in pure sand if water fertilizer is given. Some plants grow fine in sand with low light, mostly fertilizer from a lot of fish and some traces and K from time to time. Some examples can be found in Vallisneria, Saggitaria, Cryptocoryne, Hygrophilla(corymbosa, polysperma) , Egeria, Bacopa, Cabomba, Myriophyllum (some) etc. Sand is cheaper, settles easier, can be vacuumed, can be reused, can plant without problems. But sand is definitely not suitable for all combinations.
So what plants would you like to grow? What fish do you want to keep in the large tank?
On hiatus till later this year