No - this is not necessarily true about output power. I work in the field of satellite systems and can tell you that the reason that the ACR PLB transmits 5watts is because it transmits to a GEO satellite constellation, as opposed to SPOT's LEO constellation (950 miles). The GEO satellites are much further out in space, and as physics tells us, you need a stronger signal for it to reach that far out. The 5 watt signal doesn't mean that is more powerful or better, it is just what is required. My PLB, like any satellite system, is not foolproof under canopy or trees. If SPOT could have a higher power antenna, it would - but the FCC regulates this, plus the AA batteries would be wiped out in no time. SPOT is as reliable as anything, provided it is used right.Currently, no... And frankly this is it's biggest disadvantage. It operates on a 0.6W output signal strength, the same a traditional GPS uses to receive. This means that if your under a heavily treed area or in a deep, slot canyon the signal is going to really struggle getting out. The SPOT works best if you have a clear and open view of the sky.A true personal locator beacon like the ACR PLB sends out 5 watts (12.5 times more power), allowing the user to be detected even under heavy tree canopy, in a crevace, or a slot canyon. This is really the one of the main differences between the SPOT and a dedicated emergency locating device.