The Guardian doesn't put out copy for someone with the reading level of a preteen. Not that I'm suggesting it's what you want but it is the target reading level for publications like Reader's Digest. A relaxed easy going reading level makes for a comfortable read but sometimes The Guardian publishes complex content. Then the reading level becomes a little more demanding.
If you are into seriously difficult reading, try wading through mineralogy papers on the structures of sheet silicates.
