Keep in mind that there are different varietals of sinensis, and taliensis, etc. Some even have landscape implications, like purple leafed varietals that have been planted in many areas of the world.
I'd want to try to get my hands on either puerh tea bush from the northern area (I'm in Atlanta and puerh is fairly subtropical), or try to raid some of the really nice varietals that the Taiwanese ag people have developed over recent years.
Camelia japonica can be made into bad tea I believe, and from random googling, I presume it doesn't make worse tea than any tea you'd make at home regardless of varietal or species.