TireTraker TPMS any good ??

I purchased a tire monitoring system shortly after I drove the last 300 mile leg of a long trip to/from Alaska. I always did a pressure check each morning before hitting the road, but I did an additional check when I got home and found zero air pressure in the left inside rear of the 'C'. I also found a 10 inch nail in the tread. The tire was intact so it didn't "feel" any different when driving. When I thought about where I could have been stranded on that last leg, I bought 6 new tires and the monitoring system. It was about time to replace the tires anyway, but now I can see the tire pressures and temps in real time.