There are a few people (off the top iampepe comes to mind) on here that use either tiered systems for autos and photos as well as those that just transplant. I am moving towards starting everything in rapid rooter in a solo and then dropping off the bottom and planting 2/3rds of the way down into the final container. I think (but could be completely wrong) that it helps to force the tap root down and as it meets the transitional zone encourages branching rather than a straight shot to the bottom. I'm also a huge fan because on purely a practical level it allows me to fit more stuff in my space and keep say clones or seedlings further away from the lights in the tent when they get moved from my clone dome (or for seeds sprout) while I still have other stuff flowering. After a week or so, I'll drop em into final containers with to bottom popped off. I like too that I can water the cup after "transplanting" for a week or so and then start to water the perimeter, inching out to encourage the roots to stretch. Others on here just cut the bottom out to begin with and have it stick out of the final container from the get go.
