I have both the Staun and ARB deflators. Two sets of the Stauns set at different pressures for the truck and Jeep. They are more convenient than the ARB so they get used more often. I check the pressure occasionally to make sure they haven't changed and they seem to hold their accuracy.
I use the ARB when I need something greater than sand pressure in the truck. The problem I see with this deflator is that if you don't follow the procedure you can over pressure the gauge with 80psi. I haven't had any problems with the valve core.
I have a friend with the ARB suitcase compressor and I have fixed it twice for him. It has a design/material problem and has clogged both times. I wouldn't recommend it.