I've been using each individually, n I think the rapid start works a lil better than roots excell. leaves pray instantly n root mass is full n healthy during transplants.
Roots excell works awesome too, no secret.
Since rapid start smells like vitamins n aminos, hormones
And roots xl smells like a dead pigs ass I though id try them together every feed til week 3 of bloom. 1ml per gallon.
Starting tonight, hope it works!