Well, I'm making a hash of this ... wish I could blame my computer.
The problem with the Wade Giles system was two fold. (a)it had to express the 4 tones used in Mandarin by writing numbers above each sound. and (b) it distinguished between certain sounds by using a " ' " when it was asperated and leaving it out when it was not. Thus, the sound 'bay' is spelled as a bay ... but the sound 'pay' is spelled p'ay.
That beer in wade giles would be spelled Ts'ing Tao.
No system for romanizing Chinese is perfect, but the one I learned on at least indicated the tone of the sound by altering the spelling. It is no longer in use, but then neither am I. Edmund