The Perfect Switch certainly has good specs and very low voltage drop unlike a traditional diode isolator.
My rig has an idiot proof and failure prone system. It's idiot proof because the electronics monitors both battery banks and charges both as required from either the alternator or charger.
It's failure prone because they use the typical Intellitec solenoid which from my experience is a cheap failure prone product. The use of a good quality solenoid would have eliminated this problem.
My prior rig was similar but didn't charge the chassis battery from the charger. So I added a small $26 2 stage charger to the chassis battery.