The test strips generally work wonderfully and are just as precise as the Taylor test, most of the time. However, the test strips seem prone to some kind of interference. For some people they are just wildly wrong. We were never able to pin down what was causing the problem, so we mostly recommend the Taylor test these days.
Unless you are a professional, you won't use up either the strips or the drops, and both should be replaced annually, so the drop test ends up being more expensive.