ONce you go hydro you wont want to go back to dirt (if you are growing in a selling capacity at least). Putting a
smart pot into a regular pot is less than ideal. Slabs are good as you get benefits from the roots of each plant touching the roots of the others (not sure the scientific reason why this is better but it is).
smart pots are easier to move and are reusable. I use 5 gallon
smart pots win a screen of green with 5 gallons of perlite to one brick of coco and about 10 cups hydroton mixed in. I water daily but can go as long as 3 days without if needed.