I wish Niven had been able to keep writing books on his own. I loved the Known Space books but something happened to him after 1970 that was worse than what happened to Heinlein around then. I don't think the books he wrote w/ Pournelle where anywhere near as good as Neutron Star, World of Ptavvs, etc. His great disaster short story Inconstant Moon dates from that period.
Yeah but Niven's best stories were mostly shorter. (Even Inconstant Moon is a novella.) IMO, Niven and Pournelle were really great complements. Niven wasn't really a great novel writer and Pournelle ended up doing militarist fiction--some of which was OK but not as good as their joint work.