Terror of the Vervoids is really good. Time and the Rani not so much. The Mark of the Rani is somewhere in the middle. I don’t really count The Ultimate Foe as it was an impossible task for them.
I think Pip and Jane were unfairly maligned. Whilst none of their episodes were outright classics, I agree with @deltaandthebannermen that Terror is good. It’s a very traditional Doctor Who story told at pace and is probably one of the best portrayals of the Sixth Doctor. Mark of the Rani is certainly middling, though marred by the whole rubber tree incident. Time and the Rani isn’t entirely their fault. The DW Office was in a real state of flux at the time, as it was in total chaos when they wrote The Ultimate Foe episode 2. That neither works isn’t exactly their fault. Additionally, there were changes to Time that cut against what they were aiming for. As script writers, they’re no worse than many DW saw over the years, and markedly better than some.