I've used both. My children and I, both, find SL to be much more engaging and interesting overall. I think either can have as much or as little depth as you'd prefer as various topics/people/events come up.
We are thoroughly enjoying the Apologia elementary science books, by Jeannie Fulbright. Currently we are doing: Zoology 2, Swimming Creatures, up next we will do Astronomy, and then next late spring, Botany.