Agile methodologies are adapted by growing number of software organizations. Agile maturity (also called agility) assessment is a way to ascertain the degree of this adoption and determine a course of action to improve agile maturity. There are a number of agile maturity assessment surveys in order to assess team or organization agility and many of them require no guidance. However, the usability of these surveys are not widely studied. The purpose of this study is to determine available agile maturity self-assessment surveys and evaluate their strengths and weaknesses for agile maturity assessment. An extensive case study is conducted to measure the sufficiency of 22 available agile maturity self-assessment surveys according to the seven expected features: comprehensiveness, fitness for purpose, discriminativeness, objectivity, conciseness, generalizability, and suitability for multiple assessment. Our case study results show that they do not satisfy all of the expected features fully but are helpful in some degree based on the purpose of usage.