So I bit the bullet and ordered Dragy from Amazon:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I will post 0-60 0-100 100-200 1/4 60' etc - finally we'll be able to tell real difference between let's say 91 octane and race fuel etc.
Dragy claims identical to Vbox results. Down to 0.1sec and even to 0.01sec using different algorithms. At least it will be as accurate as it gets for a DIY tests. It will also record elevations, temperature, graph of acceleration, elevation, ET, etc. Most importantly results will be consistent.