I love the irony in this match, it's the episode where Karai was captured versus the final episode she has following her capture.
Honestly though, Pig and the Rhino I do prefer over Fourfold Trap. The former does an excellent job portraying Bebop and Rocksteady in this series as dangerous (before their eventual decline in the season as idiots), providing a great deal of suspense. That and the Coney Island fight is among the best of the series alongside Splinter vs Shredder and the Turtles against Shredder for the first time. While it being placed before fighting the Kraang feels off to me, I did enjoy the episode due to the intensity of the conflict; though Shredder easily dominating them in their mutant forms and Zeck and Steranko suddenly used to them are issues.
On the other hand, Fourfold I honestly can't praise too well. It's conflict was suddenly finished with a deus ex... I mean healing hands resolve. In addition, I feel not enough time was dedicated to either of the plot points; the traps were suddenly concluded exactly like Vision Quest in the trials. Even as standalone, so much time is wasted telling the backstory of the plot that there's no time for the actual traps. In addition, I'm all for Splinter saving the day with Karai being a prediction since the beginning of mine, but why of the unholy is the hands a resolve? We don't get what happened in Deadly Venom for how it affected Karai and we certainly didn't get it here either; despite the possibility of Karai gone savage, it's not well thought out at all.
Overall, the former is the better to me due to the intensity of not only Karai's minimal role, but due to Bebop and Rocksteady's presence increasing the drama. That and because they referenced Next Mutation of all things before the battles began.