American Pronunciations of "practice" Oxford advanced American English: /ˈpræktəs/ https://www.oxfordlearnersdictionaries.com/us/definition/american_english/practice_2
Oxford advanced learner's dictionary: /ˈpræktɪs/ https://www.oxfordlearnersdictionaries.com/us/definition/english/practice_1
The difference is the second vowel ə - ɪ
So which is more common and which is more American? I assume that Oxford advanced American English dictionary always give more American pronunciations than Oxford advanced learner's dictionary, am I correct?