I think there are two things in play here.
Right now, Philbert is evaluating "How does the machine work?", which would be a comparison of setup time and running time, vs. just setting up a manual grinder and doing it yourself, or hand filing. Things that could be compared by measuring how long it takes him personally to do something, versus another thing.
A completely different test is "How does it cut?" You would need a baseline (Off the roll LGX?), and lots of variables can come into play. We all have ground a cutter that looks fast, but doesn't last, or one that doesn't look sporty, but it goes forever. That's all in the setup, and will vary quite a bit.
I think that sticking to the scientific method of "One variable at a time" is good, although it does take a long time to go through all of the variables.