I've bought an onyx m92 ( http://www.onyx-boox.com/onyx-boox-m92 ) which has got me fairly close to this capability for reading PDFs (it's an ipad-sized device). It comes with a stylus which allows you to tap a specific point in the progress bar to change pages. Much easier than scanning back and forth using a kindle.

It's still not quite up to the standard of flipping back and forth in a book, but it's tolerable. I've also changed my reading flow to make a lot more bookmarks of interesting parts of the book, and use search more. Given the other advantages (portability, price of books) it's a solution that's working out really well for me, and allows me to read a lot more technical books than I would if I had to lug them about in print form.