The only benefit I found was you could start from seed in a rockwool cube. Or start with clones with small root systems.
As soon as the roots get into the water I go with straight DWC. The pump can get clogged, added heat, and more stuff that the roots love to wrap around (pump, manifold, lines...
I've used both and like the smaller individual buckets or 5 gall. rubbermaids (1 to 2 plants in ea. 5gal. rubbermaid). My only real reason is if there is a problem with one plant you can move it or work on it with out affecting the other plants.
It is a little more work but its a labor of love.
Sunleaves testers are good about 100 for the PH and 75 for The EC/TDS meter. The Hannas are also nice.
I like individual testers because if you break one your only out one tester not both. I used to use strip testers for PH and had lock out last run. I found out my PH was really running around...