I wouldn't go as far as terrible, but definitely not a great service provider. Attitude was relatively good (wasn't ice cold nor was rushed), but just doesn't have skills.
Also not buying the half-Korean thing...yes, she is mixed. To his credit, the PPS did mention that her service isn't up to par with the Chinese girls before the session started, so armed with that info, was prepared.
Positives - definitely mixed (though I don't believe half-Korean), relatively cute (6.5 face), athletic body, pretty decent English. I'd say mid/late 30s, but can pass as younger.
Negatives - So-so service/skills, very prominent C-section scar, heavy makeup, and a slight hint of odor downstairs. The $20 upcharge for being half-Korean mixed...meh...it's only 20 bucks but doesn't/shouldn't warrant an extra charge.