When I was younger, yeah, I guess looking something up in dictionary was something I did. But over the years I guess I go by context, how the words apply to the flow of the thought. Don't know how to explain it, but most of the writers I read flow in a way I understand. Now if I read books from 2 centuries ago or scholarly stuff where the writer is referring to ancient myths and "puffing himself up" and acting God-like, yeah, I would need oxford dictionary.
So I guess with the type of stuff I have read for years, I didn't use the dictionary, so I really don't miss it.
But that is not the point, the point is, the dictionary feature is a nice feature and I could see myself using it for learning new subjects and "reading some of those old puffy-type books of old".