I'm going heavy on plants for the first time on my krib and on my goldfish tanks, gravel in both. Most plants seem to grow roots no problem, but those roots are not the best at keeping things in place. It's going well, but I do a fair bit of re securing floating stem plants. Rocks and the edges of caves are my friend. Best of those I've got is a big piece of dead coral with lots of little holes, it's kept a few stem plants in place perfectly, moss and ferns call it home, and krib fry are always in their greatest concentration there.
Thinking about river silt for my next tank (same river I get most of my plants from), but the gravel is fine.