I don't know any ex-Catholics who became Episcopalians. They all joined more conservative churches if they joined a church at all. Most Catholics I know left because they were bored silly or were too conservative for their local churches. Our local Catholic church is so liberal I feel like I need to have a "Vote for Kerry" sticker on the back of my car to feel welcome.
Between those who left because the Church was too strict and those that left because it was too lenient (the changing over to the New Order Mass from the Tridentine,most often) there was a whole lot of movin' going on in the 70's especially.
That was probably better than the decade that followed when those who thought it was too lenient just stayed and proclaimed that whatever they did or said was just fine with God, all He seemed to require was that we all be "happy little Catholics". Ugh!!
I do think things are getting much better as the old guard dissident bishops are dying off and the poor uncatechized or discontented catholic groupies are appalled and disturbed by the orthodox Catholic Bishops,who are replacing them. Many are now disgruntled and leaving although some are still fighting furiously.Imagine that!!