I’ve heard good and bad, although some of the bad has been from ultra traditionalists who suspect anything that has happened in the Church since the fall of the Holy Roman Empire.
The Movement began in Spain as a way of educating the faithful about the Faith and encouraging a more active participation in the Sacred Liturgy. In the USA in the middle 1960’s and early 1970’s it became the springboard for many a liberal cause that drove some into the waiting arms of Protestant sects and the errors of individual determination of what they would and would not accept. From what I have heard, most Cursillo Chapters have returned to a Faithful Catholic positon.