I bought one when I first started reloading a few years ago. I think that I have used it maybe 4 or 5 times. Do I think they are worth it, no, not particularly.
I made a crude one years ago, used it for while, but I don't believe bullet runout is as critical as some think. With 284 brass, I roll it on a flat surface occasionally - apart from with new brass, the bullet tip rarely wobbles.
Remember many years ago with ADI ammo some of it ran out as much as 13thou.
Never made any difference to the accuracy but then we were not shooting F Class either.
Really cannot see 2 or 3 thou making any significant difference to accuracy that would be measureable and attributable.