It seems like there's a distinct difference between the breed direction and I am wondering if anyone has experience with both?
Sorry, I have very little knowledge of this breed, there are not very many of them in the UK. I have read that the bubble of popularity that the breed had in China has burst, and the enormous prices that they were fetching has tumbled. There are pictures on the net showing lots of them in a Chinese rescue centre.
I have no personal knowledge of Tiberian Mastiffs but there were three owners on the Epilepsy List who had dogs of that breed, all in Europe, and all had epilepsy. None were related but apparently it is common in that breed. One girl in The Netherlands sent me all the Phenobarbitone for my epi girl that she had left after her dog had to be euthanised.