Lots of folks, perhaps even a majority who have surge protection have hard wired units and you simply can not see any evidence of such a system walking around the CG. I would wager that the overwhelming majority of hard wired units are in fact EMS. You can buy a Progressive Industries portable 30 amp EMS for around $300 with the hard wired and 50 amp systems going for a couple of hundred more.
I have never understood the folks that brag about never having had a problem, thus not needing this protection. They probably have had low voltage issues but simply never were aware but the damage has been done and will ultimately be evidenced by premature failure of pumps, bells and whistles that have been damaged. AC systems are particularly sensitive to low voltage which will shorten their working lives dramatically.
If you just go to the same CG every trip and the location has good stable power you probably won 't have a problem.... but you could. We travel to different locations almost every trip and frequently find power pedestal issues. On our last trip my PI EMS detected two open neutrals, one open ground and one reverse polarity all in the space of 60 days. Any one of these faults undetected had the potential to be a very expensive disaster.
It is a choice we all get to make and hopefully before you cook thousands of dollars worth of electrical/electronic toys. The one thing I do know is that the need for protection is NOT hype. You pays your money (or not), and takes your chances but going unprotected strikes me as a very penny wise - pound foolish risk.
As always.... Opinions and YMMV.
:C
