I have installed one and am thrilled by it. Not only will your compressor last much longer it will also significantly reduce the startup noise(which means less wear on the motor).
You will always have naysayers on TOV, so I recommend watching this video for the best description on the benefits and how to install.
https://www.youtube.com/watch?v=MDp1g8r8IVs
Most RVs need it for camping grounds due to the max current limitations. It also has excellent solid state protection against electrical faults like single phasing.