Cindie,
DD10 used 2 of the apologia elementary books with co-op and while they were good and she learned much, we decided we greatly prefer living books! We’re using only living books and nature study now with her and ds7 and I don’t intend to change until they are much older.
Incidentally, I just hit the jackpot at our BooksBloom event and scored 15-20 living science books. Fave authors – Arnosky, McClung, Selsam, etc.
IMHO, yes it is quite enough and for us, even preferable.
Blessings,
Christie