While I enjoyed this episode, it wasn't a stunning success that made me want to watch it over and over again, like many other King of the Hill episodes. However, "Four-Wave Intersection" is a pretty good episode, and shouldn't be skipped.
Boomhauer episodes are few and far between, and usually involve him as a secondary character, so it was nice that he played such a large role in this episode. It also went a long way in developing Boomhauer's character, which hasn't been a priority since, well, ever.
Oddly enough, Joseph had some of the best lines of the episode, with his explanation on why he was at the Hills' house instead ov his own ("My dad has the heat cranked all the way up! He said something about fighting fire with fire, but it wasn't working for me!") and his interpretation of the words to the commercial jingle for directions to the water park.
While the idea was pretty funny that the older kids were insisting Bobby, Connie and Joseph couldn't go on the water slide over something as asinine as not being local, I didn't really understand where the joke came from - they didn't really made it clear where exactly this water park was - I thought it was IN Arlen, but Bobby's an Arlen native so they should've let him in. If it was outside of Arlen, where outside of town? I know they got on the highway, but never said how far from Arlen they were.