Personally if the books concerned are of artistic or historical value, then it's likely the tactility would amplify that value, and it'd make sense to possess physical copies. If the book's value was generally in its contained information that you can reference though, e.g. textbooks, manuals, then I'd judge the electronic version to be at least equivalent in value to the physical copy.
There's evidence that reading from a screen makes it harder to remember and understand what you read. I would still prefer books even if they didn't have this advantage, though. :)
Interesting. Personally I don't even note where I am or was in the book. That point on a physical book allowing for more contextual knowledge at one glance than a screen feels weak though. I could easily adjust the font size to allow for more contextual info at once, right?