Our own comparison (page 9) of recent OFSTED reports on postgraduate teacher training suggests that college-based courses rank higher in the judgments of inspectors. That might be expected since they are longer-established and less experimental. But these verdicts probably tell us more about the trainers than the effectivenessof the teachers they produce - or the attractiveness of different routes for different recruits.
Total immersion in school life may provide better opportunities to absorb the craft of teaching - as its fans claim. And training that is in effect the first year in a new profession, rather than the final year at college, may also attract those already more confident or competent. The result might even be teachers that are as good or better than those from courses which have earned higher OFSTED ratings. But that doesn't mean that all the teachers we need can be trained that way.