Disappointed there are not more responses to this thread, but I am a fan of trackball keyboards. I have long considered getting that Cherry G80-11800, but the Cheery switches and non-ergo layout sway me towards not adding it my collection. Plus a lot of older trackball keyboards suffer from low DPI.
But I love a good trackball keyboard more so than touchpad. A touchpad is not ergonomic at all, and will cause your hands to hurt at some point because your hands are not meant to move around on flat surfaces. The Apple MAgic touchpad does have great features, but the darn thing makes my hands hurt after awhile.
Here is a picture of my favorite trackball keyboard, my Maltron. The trackball is in such a position that you rest your hand and navigate with the numberpad as well. Overall, I find this setup to be one of the best navigation options around.

Then I experimented with the Kinesis Advantage and an Apple Magic Trackpad in the middle. While having the trackpad in the middle was convenient, it still made my hands hurt.

Lastly, trackpoints. I love a good trackpoint on a laptop, but the only keyboards I would buy with a trackpoint, the IBM Model M13, was made for monitors with less pixels and is not that ergonomic.