In addition to draw length, release, and potential string material and size differences that others have already mentioned, don't overlook that (at 10 gpp vs 9 gpp)you're also shooting an arrow that's about 50 grains heavier than the test arrow.
I chronoed one bow in my life about 30 years ago. It was supposed to shoot about 190 fps plus at my draw length and I "only" got 180 fps. For the next few months, I was overdrawing considerably trying to get more speed out of the bow, and my accuracy went to pot. Finally said the hell with it and never looked back.
It's sort of like EPA auto gas mileage estimates. If measured the same, which they supposedly are, they make for a nice comparison among various vehicles. However, few people get the mileage advertised,