I have one. It works.
If you're loading for something a little offbeat, like a wildcat or 7x57 or 7.62x54R they are extremely helpful. They are also helpful if you have the curiosity gene and want to do basic experiments.
If you're loading for your 30-06, there are plenty of good loads available already, and you're not likely to do much better.
From all the evidence I can find, the piezo and strain gauge methods of measuring chamber pressure are practically interchangeable as far a quality of results go, and both are much superior to the old CUP method. If you're going to do serious pressure measurements, you do need to control the temperature of the firearm. I strap a thermocouple to my barrel, just forward of the receiver.
This may help. 
