To what extent can faithful Catholics criticize Vatican II?

Vatican II is one of the most controversial councils (perhaps falling behind Trent) and has been criticized widely by Catholics due to the stance it takes on how the church should interact with society. To keep in line with the teachings of the Church, to what extent can a faithful Catholic criticize what the Church defined as doctrine/discipline at Vatican II? ---- Related: https://christianity.stackexchange.com/questions/32008/for-catholics-who-object-to-vatican-ii-what-are-the-key-issues and https://christianity.stackexchange.com/questions/35290/what-is-the-status-of-catholics-who-reject-vatican-ii-are-they-considered-heret