I have a TM-1 that I have used for many years and have built maybe a dozen wheels with it. I have not had any problems with those wheels. I am about to build my first set of carbon clinchers and became concerned about the accuracy of the TM-1 being that the pair of rims cost $460. So I built a calibration jig to check it. It is pretty accurate when measuring a bladed spoke like a CX-Ray but is reading about 20% high on round spokes.
so there is a good chance some of my wheels are under tensioned. I am glad I built the jig, it will give more confidence going forward.