I agree with Ben about the numbers. Here's what I saw:
Variation in the FC/TC did bounce around a bit but in EVERY test FC=TC meaning there's no CC. The difference wasn't very great either...3 to 4. No biggie.

All but one of the pH tests were within a couple of tenths--7.5, 7.6, 7.9. The 7.9 is almost an outlier but it's still not far away.

Alkalinity is also really, really close...basically the same.

The one difference was CYA being 40 in one and 55 in another--and we see such wild swings all the time. My view on CYA is I do it exactly the same way every time and use THAT as my baseline. And I always run the test twice, at least. Just pour the mix back into the squeeze bottle and then squirt it into the black dot vial again.

Since I have rarely any trouble over the summer, I'm likely to stick with what works for me. Sometimes high CYA/High FC running is necessary....ask aylad!...but running at 30-50 CYA has been effective for me. Poconos and I live much further north than aylad or PoolDoc, or even Watermom and pools do behave somewhat differently up here than they do in the South. Adaptability, though is key.

Carl