ACT also sells Mitutoyo - Both my .0005 and .0001 DTIs are from Mit. If you check out Youtube, you will find some DTI shootouts. The lesser brands can suffer from parts issues as above, but they have a very low entry $$$ and read as sell in the .0005 models. For the more accurate needs Mitutoyo and Interrapid are the best. I have seen some probs with the a friend's newer Starrett .0001 indicator - but that might have been an anomaly.