With the ebb n flow you can move the plants around and get different angles and move the shorter ones in and the taller out to create a stadium effect unless you use the slab of rock wool method.
Very little to go wrong with bubble. No pumps, no dry periods...... just check the reservoir and watch them grow......sssshhhhh I wish. Lots of training, can't move around (unless on wheels).
Used both and prefer bubble...
Peace