disenchanting, disillusioning
Webster's Dictionary (GCIDE)
convincing \convincing\ adj. causing one to believe the truth of something; having the power to influence or convince; cogent; -- of evidence or testimony; as, a convincing manner. Opposite of unconvincing.
Note: [Narrower terms: disenchanting, disillusioning] [Also See: persuasive.]
Syn: cogent, potent. [WordNet 1.5 +PJC]