That's a surge protector only. It doesn't protect you from other common electrical problems. If you look at the info on the link I provided in the earlier post, you'll see the detail on how the more expensive device protects your coach.
As an example, if the pedestal has a bad neutral connection, when you plug in, you can fry most of your appliances. A surge protector will not help you with that problem. In the summer when everyone in the campground is trying to run all their air conditioners at the same time, and power drops below 105 Volts, you can damage your air conditioner compressors. A surge protector will not protect against that. If the pedestal has an open ground, you could possibly end up with a very dangerous condition where the "skin" of the RV is electrified. A surge protector won't help with that.
These things don't happen every day to every RV'er, but when things go wrong at the pedestal, it can cause thousands of dollars of damage and create hazardous conditions.
If you use the same seasonal site all the time, and the park is well maintained, your risk might be lower. If you visit lots of parks, eventually you'll run into a bad pedestal.