I really want to use and don't mind paying for Waygook, but their method is very shrewd in not answering emails and the 1 month subscription is not really a one month.
By the way, a shrewd decision/observation is one that's good/astute. Shrewd means that they used good judgment.
shrewd
SHro͞od/Submit
adjective
adjective: shrewd; comparative adjective: shrewder; superlative adjective: shrewdest
1.
having or showing sharp powers of judgment; astute.
"she was shrewd enough to guess the motive behind his gesture"
synonyms: astute, sharp-witted, sharp, smart, acute, intelligent, clever, canny, perceptive, perspicacious, sagacious, wise; More
antonyms: stupid
2.
archaic
(especially of weather) piercingly cold.
"a shrewd east wind"
(of a blow) severe.
"a bayonet's shrewd thrust"
mischievous; malicious.