I'm not going to enter the debate as we all have different views on tyre pressures like we all have different views on our respective tugs, trailers, fridges, tyre brands etc.
Haven't you already done that by replying to this thread?

What I would like to point out tho, is the pic a few posts above........
How susceptible is that sidewall to staking at that low pressure especially in burnt mulga country or rocky country.
My view, fine for the beach, not the desert.
Food for thought.
My food for thought.
In my experience a sidewall is vulnerable regardless of the pressure in the tyre. However saying that I've personally had less problems with staking of sidewalls or damage from gibbers etc with lower pressures.
If we use a balloon analogy it is harder to burst an under inflated balloon than it is a fully inflated balloon. Try it of you don't believe me.
All of the tyres I've had punctures in have been at highway or close to highway pressure. The same tyres at reduced pressures have never had a problem, and this has usually been in much tougher gibber country. Even Coopers, yes Coopers with high pressures get punctures, FACT!!!
If you are getting regular punctures at highway pressures on dirt road and you are prepared to listen to heard earned experience it costs nothing but some time to drop your pressures 15-20%.
Be brave and give it a a go, in my experience you WILL be rewarded with less punctures.
If you don't believe me on how much of a difference tyre pressures make, go for a drive to Stockton Beach and see how far you get with 30PSI in your tyres. If you don't want to make it past the entrance track leave your tyres at their highway pressures.
Jason