Have either of you used the "CD-ROM" versions they had before the 2011 when they stopped that version? It was much easier and faster to navigate then a PDF file is. It had a "tree" on the left side of the screen that you could quickly click your way through the tree reading section titles. With the PDF you can't do that, you need to know more detail of what you are looking for to put into a search and come up with the right results the first time. If I did a search for the word "white" in those CD-ROM it would not take 2 minutes it would have found all 68 of them in less then 2 seconds after hitting enter, unless maybe you had a really slow computer.
With 2011 NEC they did away with the CD ROM and offered a subscription service "NEC plus". I though it took a little bit of a step backward when talking about how easy it was to navigate through the code, but still was better then a PDF file for navigation. Then just a month or two ago they decided to stop that service - even though many people are still using 2011 nec
Now my only electronic option for 2011 is PDF files, and I just don't like it after having something that was easier to navigate. But I need to get into the 2014 anyway as it will go into effect very soon here. I think they have an E-book version for 2014 that has basically replaced the CD-ROM's and the NEC Plus of the past. But probably will have issues with it as well once 2017 comes around because they will likely end services or support even though some people will not switch to 2017 NEC right away