Just got my new GoGo TT-1. Two badger paws WAY up!!! Very fast, accurate, loves the E string, red display changes to green when in tune...
Beware the infamous "color-change" tuners. Do a search here. They are among the most inaccurate and once they "decide" the note is correct and change color they basically suppress and ignore small changes. You can demonstrate this by having it change color to indicate correct intonation and then intentionally de-tune by more than a few cents. The tuner will typically continue to indicate correct intonation.
Jeff, FWIW, the Korg OT-120 allows the player to use their ear thanks to its sound back feature. It's basically a drone that changes to whatever note you're playing as you play it (and it's sensitive to whatever octave you're in.. particularly good for upper thumb position intonation, where the ear might get a little funky on its own). You either match it right away or adjust if you're a cent or two off (it keeps the player very honest, intonation-wise). I also agree with your method of using harmonics (sometimes open strings too).
Now, that's a VERY COOL feature! Thanks!