It could be, but remember there is also a psychological factor too! It may be that you're thinking too much about it. Keep these things in mind
More LEOs are using laser and CO now. Passing a cruiser on the side of the road with a victim, driving by an apparent speed trap, or seeing a LEO coming at you on the other side of the road doesn't guarantee an alert!
Speed boxes on the side of the road are battery operated, and therfore their output level is not constant. Some days, on a fresh charge you might pick them up a mile away. Other times the same box might not trigger an alert until you are upon it.
Traffic density can significantly affect your alert time. Following closely behind a large vehicle can seriously diminish the amount of microwaves that reach your detector.
Mounting CAN be critical. Try to mount the detector level and with a clear view of the road. Often what "looks" level to your eye is aimed straight at the ground 100 ft ahead when you check it with a level. PLease find level ground to park on before you check that your detector is level, otherwise it's all for naught.
There's no guarantee you'll pick up laser, even if you're targeted.
Running in auto or city mode can and will reduce sensitivity to X and K. You should still get enough reaction time with a good detector, but not near as much as in HWY mode.
There are multiple KA bands and not all detectors are equally sensitive to all bands.
Detector watching (we are all guilty) will almost certainly lead you to beleive your detector is too quiet. Watch the road, and react to real warnings instead of anticipating them all the time.
Of course, sometimes there is a problem with the detector. After all, heat is the enemy of digital equipment, and we subject our detectors to a LOT of it. Sometimes they do fail. that said, I tend to think it's usually easy to tell when something really goes wrong after a couple of trips on the highway. Hopefully it's not too late. in the case of our Belscorts, they are all too happy to declare when there is a problem...sometimes when there isn't even one.
Feel free to ignore this post...these things were just on my mind tonight!