Manual or Auto,
All depends on how many tires you think you may need to cut. Let say your new 1/8th tires come out of the box at 82 mm, and you need to start out at 76mm, yea, you can hog it all off at once, but that is a lot of heat during cutting, as for me, auto is the only way to go, it cuts, I continue to work on the car.
I have heard the GQ truer is of good quality, if I were to get another, it would be the GQ or the Integey with the HUDY bit of course.
Smitty