It isn't perfect, but it's a lot better. I understand why there are issues. What I am not understanding is why the basic pdf file and "Adobe pretends it can smoothly convert pdf to text" file are so much more readable than results gotten from calibre, which is supposed to specialize in this. It reminds me of when I first learned to use a word processor. My father knew all the bells and whistles of the word processor and desktop publishing software he was introducing me to, and I was boggled by one rather minor detail.
On a typewriter, one gets 66 lines to the page, single spaced. Subtract 12 for a one inch margin at top and bottom, as there are six lines to the inch. This leaves 54. Divide by two, as I double space, and that means I should get 27 lines to the page. And, indeed, I did when I used a typewriter.
My father's programs could get me anything from 24 to 33 lines per page -- that is, anything except 27 lines. I did not comprehend why all this high falutin' newfantled tech could not easily duplicate my standard default on an old fashioned typewriter.