I've had some decent success converting PDF to epubs with Calibre. One of the biggies is playing with the wrap setting so you don't end up with paragraphs turned into disjointed sentences and sentences turned into phrases split across multiple lines. Calibre defaults to .40 for that setting, and .05 seems to work much better -to make matters worse the hint for that setting made me want to increase rather than decrease the setting...
The find and replace makes it fairly easy to get rid of the built in page numbering and headers and/or footers that PDFs seem plagued with and allow the ereader to do the page numbering as one would like in a variable sized text based format like epub.
If my experience is typical, expect a good evening wasted putting it all together the first time around, but very gratifying results when you get it right and can enjoy the benefits of an epub rather than the aggravation of PDF viewing. I bet the next one I do takes no more than 15-30 minutes of twiddling about including Sigil.
A little work with Sigil can help clean things up if you'd like a decent table of contents and chapter headings as well.
Last edited by TechniSol; 11-28-2012 at 12:48 AM.