Benefit of using grodans over hydroton

A friend of mine uses 6" grodans and perlite in hydro (flo n gro, 4 gallons buckets). He claims its much better than using hydroton. Anyone know what the benefit if any of using the grodans and perlite are over another medium?

I set my new hydro setup using grodans and perlite like he does... so far so good a couple weeks into veg. His plants have always looked really well and produced great yields and quality bud so I figured I would take his advice and give it a try.

It all depends on what style of hydro you are doing. I personally DWC so I use hyroton.