Ergons have helped a whole bunch of people (myself included). Even so, on a long enough ride you'll be wanting at least on other hand position to change things up a bit.

Your correct in your observation that your existing controls will work on a trekking bar. I've read where some people have had to swap out stems as well (for reach). I've also seen at least one pic here on the boards of trekking bars w/Ergons installed