With Hyde almost being the central character of the season, the plots work very well, including this one where Hyde's sister is introduced in a naturally hilarious way. Hyde and Angie's war was very funny, as was Kelso's "I'm too good looking" running joke.
Eric's plot was also very funny, though Eric seems to be getting more pathetic as the show goes on. The roller disco plot has been done before however, and this was nowhere near as good as the previous one. The reactions of the gang and Red were very funny however, and overall the episode is, as always, a riot from both plots.