Orbit manifolds that aren't "full flow" have more restriction in the adjustable ports than the free flowing versions. The adjustable 8 port ones like you originally got are designed to be hooked up to household water pressure, @ like 60+ psi. So, usually the smaller more restrictive ports wouldn't matter anyway and you wouldn't notice a lack of flow as much with a proper irrigation system using them. However, when you hook up a weaker 500-1000 gph mag drive pump that barely outputs maybe 2-3 psi, sure.. your gonna notice it not performing as well.. I'm guessing the floraflex manifolds are more open, but kinda doubt they are designed for high psi applications like the orbits. I could be wrong, and unsure of the max rating..