Having used both the flow-thru and now the cap sensors, I can tell you that the caps are much easier to use. The air flow through the flow-thru was seemingly obstructed and was very slow at accepting air. They stuck out beyond the rim too which meant I had to be very careful not to park to close to a curb or risk breaking off the sensor causing a rapid deflation event. The way I look at it is...with either sensor, the cap must be removed to inflate a tire so why have sensors that require metal stems and have the risk of breaking off if snagged up against a curb. JMHO.