regulates low and high voltage instead of just tripping like the EMS it has more value. Am I looking at this correctly?
I think you still need the surge protector - not sure if you are confused about what all these different devices actually do - so maybe not looking at it correctly. These regulators will keep you around 120VAC if your incoming voltage is between around 90 and 140 maybe - see my previous post near the beginning of this thread. A surge protector not only protects from high voltage but low voltage - I believe most claim to work between 108 volts and 132 volts and if you go over or under it cuts off the bad power. You can still get extremes of high or low voltage that a regulator is not going to be able to correct for. So a complete system would be more desirable. What the regulator does is keep you on power when there are voltage fluctuations that go over 132 or under 108 - keeps you closer to 120 - and the protector does not trip. If you get a big surge or very low voltage the regulator is not going to protect you. In my opinion we need every advantage we can get. A small price to pay to protect all our expensive gear we might have in our RV. If don't have valuable stuff to protect then you don't need any of it. You can run on solar and batteries as some choose to do. We like our modern conveniences.