If you prefer a hijab that's less slippery and has a bit more thickness and opacity, the Classic Chiffon would be ideal for you. It has a slightly textured feel and offers a bit more opacity.
On the other hand, if slipperiness and sheerer fabric aren't concerns for you, and you're looking for something soft and lightweight, the Premium Chiffon is a great choice. It's softer to the touch compared to the Classic Chiffon.
To give you more insight, the Classic Chiffon is a bit thicker and more opaque than the Premium Chiffon, with around a 30g difference in weight between them.