No water changes/loose pieces floating around/being pulled up
No cycling the aquarium
No fiddling with CO2
No having to buy a lot of plant material initially
No transition from emergent to submersed states(some plants will, but with good CO2, this is greatly minimized)
No extra electrical cost running other equipment during the dry phase.
Can do it outside in a tray even.........
Filling the tank:
It takes about 2 weeks for the Hc to root well and produce new leaves above the surface, they are putting down roots initially, so you do not see that part.
So be patient, the same is true if you do his the traditional way and not via the DSM.
here's the tank 3-4 weeks after filling it up and pearling is intense, there's no transition phase at all: