OP:
I use Furman exclusively. The SMP feature is a very effective noise filter as well as excellent surge protection. Living in a lightning prone area that’s the only thing I can recommend for high end gear. In some places where I’ve lived I could definitely hear when it was not being used.
The isolation transformer is good, but I prefer to use the voltage regulation (AR) features like this unit. That keeps a solid voltage coming to my gear regardless of HVAC or seasonal usage, something an isolation transformer alone cannot do.
Best,
E