I don’t know of any private trackers on i2p and have just used Postman mainly (the other trackers have very limited content). Postman is OK but not nearly as good as regular private trackers. If what you want are blockbuster films and the latest TV, you’ll be fine. Anything particularly nerdy you will probably find too.
Also, there are outproxies that provide access to clearnet. The public ones are usually overloaded and slow though.