I prefer hard copy, i can easily focus reading if i can actually see it. i mean as a solid material.
Soft copy is usually cheaper so I don't feel as wasteful when I read it once and give it away.
I do both. Hard copies and if there's something I want to keep I scan it or download it. Hard copies don't take immediate focus and I can look at it at my leisure. I can also make notes in the margins. When I donate my mags to others they tell me they enjoy my comments. Things like FFRF newsletter and the Humanist magazine I like to read on an ongoing basis and when I am ready.