Right off the top, I am not sure the "plain" Towa and the electronic Towa give equally reliable results. I found the electronic version completely unreliable. I have never tried the non-electronic version of the gauge.
So far, knock on wood, the drop test has worked well for me. Like Suz, I find it helps to just ever so slightly over tighten.
As for bobbins, I bought the Glide magnetic bobbins when I first loaded my longarm, and thought the machine was broken as I could not fix tension issues. Turned out the magnetic bobbins are sometimes over-magnetized and create way too much drag, or high bobbin tension. I have never used the things since.