Napa has been calling the Reflex and Sensatrak the same thing for 2 years because Monroe won't license them to stock the Reflex. So when people come in looking for the Reflex, they steer them one step down. The Sensatrak is still better than stock, but the Reflex valve response time is 100 times faster than that Sensatrak.
The sensatrak and most conventional struts use overlapping groove valves, so the strut has to compress to a certain point before responding. The Reflex uses a shock sensor, then opens an automotive type valve immediately. The difference in launches for us would be the most obvious. No rear-end squat in comparison to old valving styles.