A visit to the Letort is always worth it - every PA FFer needs to make the pilgrimage.
Worth it? Well, go there with an open mind. It's not about catching fish. In fact, don't be surprised if you don't see any fish at all (hint: sit in one spot and watch the water). The banks are wet and can sometimes be a tough slog during summertime, I like a wading staff for the wet meadows. Winter can be easier to fish as weeds and meadow grass are less. The stream is just physically tough to fish. Please avoid wading on the few gravel areas in Nov-Mar as these are managed spawning areas.
My main advice for Cumberland Valley newbies is to understand that the fish in our famous limestoners are mainly bottom feeders. You might get lucky and find rising fish, but don't expect it.
There is a lot written on the forum about Letort. Use the Advanced Search to read up on Letort.