So you can read and read all you want, but until you experience it yourself it is a bit hard to believe. My local store actually carries all the tests except the powdered chlorine test. They even sell really large bottles of some of the reagents for a great price.
They use drops to run the test, the values were so off I was worried for a bit
FC 5 --- My test - 5 (great!)
pH 8.3 -- My test 7.4 (had my wife double check)
CH 90 -- My test 190
CYA 100 -- My test 45 (had wife double check)
They were recommending that I add 42 ounces of acid which would have sent my pH below 7
So to all you skeptical new folks, believe it - your pool store test can literally be totally off.