A ‘hard’ SUP made most commonly of epoxy, will generally provide a significantly better feeling of glide than an inflatable SUP. Being heavier, it sits ‘in’ the water more than ‘on’ the water and therefore is a more stable experience. Futhermore hard SUPs are not as thick and have less windage – they will hold their course better on a windy day.
From years of experience our conclusion is, if you have roof racks and storage space, we will always recommend a hard board over an inflatable board.