We run the Hughes Watchdog 30A, and it has always worked perfectly. I will say that there is NO slack; it will cut us off RIGHT at 30A. It's doing its job, and I'm happy with that. We have gotten pretty good at managing power, so it doesn't cut us off that much any more. I absolutely love the Bluetooth control and monitoring. If we trip, I can pull up the app and see exactly what's going on, as well as reset it. No more going outside to reset a breaker, and no more worries about sketchy RV park power poles.
Last trip out it cut us off a couple times because we were running a heater. I used the draw monitor on the Hughes app to show the family how many amps everything uses so they could learn what they could and couldn't run all at the same time. DW tried to use her hair straightener while the heater and ice maker were running. No good, and she did it multiple times. So I pulled out the app and walked around the camper turning things on to show how much we had left. 30A runs out QUICK when you're running high draw appliances (microwave, heater, ice maker, coffee maker, hair dryer/straightener, water heater on electric...), and even with the Greyhawk's built in energy management, you have to be strategic in your usage.