My personal experience about cashing travelers checks in HK is a little different. The banks charge a service fee but it was nowhere near HK$100 for each check. If I recall correctly, it was more like a HK$50 service charge for the entire transaction. The hassle is going to a bank and waiting in long lines. Also, most large department stores (like SOGO) will cash travelers checks with no service charge but their exchange rates are a little lower.