For soil they are fine- I hate them for deeper reasons. 99% of that is mess.
In the brewery we used rice hulls for stouts. They help heavy recipes pass threw the mash and not get stuck. For this reason they are a life saver. You put them at the bottom or mixed in the grain after it is milled. In this scenario the are totally worth the mess even though food grade rice hulls are more expensive.
In the nursery, again mostly the mess. Growers use rice hulls as a form of mulch now. So there is an inch of hulls on top of soil.
Taking on/off trucks, moving around the store and watering are all an absolute headache with rice hulls.
I have rejected plenty of perennials and and even shrubs that perished during transport because too many rice hulls piled on and rotted out plants on transport.
Besides that im sure they work great as an additive to soil. _I almost always advocate using the most inexpensive thing you can get.
But i dont think there is much your getting from rice hulls other than a bit of texture in the soil that provides a healthy habitat for soil life.