Hi tiki, I don't know anything about Hess except that they appear to be a major recruiter/organization in Taiwan. I taught English in mainland China for several years, and on the occasions that I met foreigners who had previously taught English in Taiwan, NONE of them had anything positive to say about the experience of living and teaching there.

Keep seeking information and satisfactory answers to your questions before signing a contract and boarding a plane at your expense. Good luck!