It is a great piece of equipment. I think it should be essential for reloading especially is you are loading wildcats. It is always nice to know what the pressures are in YOUR barrel. Sure beats reading primer cups. At the very least think of it as another tool to aide you in shooing like laser range finders, chronographs, or ballistic software. You can go without it, but it is nice to know the information these give you.
The whole setup does not cost much more than an average factory rifle, so for the price of one gun you get pressure testing equipment (assuming you have a laptop computer).
I bought one two years ago. The only problem I had was the strain gauge wire broke off, but that was my fault for not waiting the 24 hours for the glue to completely set. Either that or I did not clean the surface of the barrel properly. The connector was flopping around and the wire could not handle the recoil and broke. Since then I have not used the system. I already had the data I wanted. The other thing is the strain gauge glue dries after you open it so glue up all the guns you want at the same time.