My history... When I had trailers I never had surge protection.. A nearby lightning strike took out my Air Conditioner. Thankfully it was a low cost unit and I had a spare.
Now I have a nice high end unit, not the one I want, but well the price was right. (I got a non-working one and fixed it).
I would recommend an HW-xxC from Progressive Industries where XX is either 30 or 50 depending on your RV's power cord.
WHy HW: (Hard wired) and not portable.. You never forget the HW.. Easy to forget the PT's if it's a quick overnight. And the HW's never grow legs and walk off, PT's (Portables) have been known to get "ported" when you are not working
WHY PI: instead of TRC (I have TRC) PI has lifetime warranty. TRC is 1 or 2 years (Forget which) NOTE NO complaints on my TRC