I have two of the Progressive PT50X units. One is in service full time and the other is a spare. I started out with PT50C's 8 years ago and both of these sacrificed themselves a couple of times and the warranty replacements were the PT50X's.
Where I am hosting right now others were complaining about "power surges". Actually they were commenting on flickering lights, etc. My PT50X showed it was actually low voltage. This happened 5 separate times this past weekend.
The campground manager had the campground system checked and all is ok and now he is waiting on the power company to install a recording meter on the incoming power to isolate the problem. The campground is virtually empty right now since this is our slow season until the weather cools off a bit so it isn't a system overload issue. It always seem to happen immediately after rain starts so something is obviously getting wet that isn't supposed.
Obviously I vote for the Progressive EMS.
2006 GMC 2500HD CCSB 4x4 Duramax/Allison, Titan 52 gallon fuel tank, Prodigy Controller, B&W Companion Hitch
2010 Jayco Designer 35RLTS, Cummins/Onan RV QG 5500 EVAP, Progressive Industries EMS-PT50X, TST Systems 507 TPMS, RV Flex Armor Roof