Yeah, I’m not at all surprised the variety would behave differently in your much different climate. Mine ripen in cool weather and won’t be ready to harvest until first week of Nov. They don’t even tend to drop much and stick to the trees over-winter which pleases my birds.
However, this year I’m having some other varieties of fruit drop early in spite of a late spring without achieving top flavor. I assume the excess rain and cool weather is somehow related to this.
I find refractometers somewhat helpful, if only to compare quality year to year and establishing causation to the fluctuations in quality. However, once you use one for a while your palate becomes almost as accurate at applying numbers to the sweetness.