I use the old visual inspection and quality tyre pressure gauge routine before every big trip. I check tyres religiously when I'm on a big trip in the bush and change pressures as required. My last puncture using these techniques was back in 2002 or 2003 on the Old Eyre Highway from some abandoned fencing wire from memory. Tyre pressure monitors wouldn't have let me know then anyway. Each to their own but those with monitors, don't forget to visually inspect your tyres as well.